Sci Nutri 132 Chapter 1
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Introduction Nutrition is one of the most powerful ways you can improve your health Use trial and error to find how things work An Ecological Perspective Meet the Nutrients Nutrients Substances that the body uses for various purposes Essential Necessary to life and the body cannot synthesize it itself Water Need the most of this nutrient Gives form to cells, cools us, excretes waste, dissolves substances, and provides a solvent for chemical reactions to take place Macronutrients Nutrients we need in large quantities 3 main nutrients: Carbohydrates, fats, Protein Carbohydrates Supply energy Burn it as fuel Only fuel the brain can use Nutrient in the shortest supply Simple Sugar Rapidly absorbed into the blood stream Complex Polymers of sugar Chains of simple sugars Ex. Starch, fiber Slower absorbed in blood Longer lasting source of energy Fat (Lipid) Supplies energy Burned at low intensity
Contains a lot of calories A unit of energy Not used as fuel for the brain Common and familiar fats Ex. Cholesterol, a sterol, is well known in heart disease Protein Body has most uses for protein Form muscle and connective tissue, bone and skin Important chemicals and regulators Enzymes The most vital chemical regulators throughout nature Energy Used for movement, growth, brain function, chemical reactions Stored in the body as chemical energy Found in the 3 macronutrients Found in alcohol Micronutrients We need in tiny amounts Vitamins Fat Soluble vitamins A, D, E, K Water Soluble Vitamins C, thiamin, riboflavin, niacin, and folate Organic Contain carbon Minerals Inorganic They contain no carbon Major minerals Needed in relatively large amounts Trace minerals Needed in tiny amounts Nonnutrients that affect health
Phytochemicals May help prevent cancer, heart disease, and other chronic diseases Beneficial, but not nutrients Not essential for life Nutritional Assessment Looked at by a dietician Individual recommendations are given that apply to ones specific life style Anthropometric measurements are taken Height, weight, body fat Biochemical Tests Blood and urine tests, blood sugar, blood cholesterol, and hemoglobin Clinical data Ex. Angiogram, EKG, which evaluate heart disease Dietary Find out your habits and what you eat The Science of Nutrition: The Process of Scientific Discovery Helps us discover knowledge Provides reliable information The Problems of Anecdotal Evidence Evidence that is our personal experience Personal reports are often unreliable Placebo A drug or other substance with no inherent treatment value which affects an individual through the psychological power of their belief in its efficacy Any supplement will have a safety risk Anecdotal evidence can be useful, but it isn't reliable The Scientific Method Hypothesis An untested working assumption that serves as the starting point of scientific investigation Repeating the process until one finds the info they need Experimental Design Experimental Group The group that receives whatever treatment is being studied Treatment Group
The group that receives whatever treatment is being studied Control Group The group receiving no treatment, the normal Outcome The measure being studied in an experiment What the experiment shows us Experimental Design in Nutrition Case Studies Prove nothing, but give direction for research Anecdotal evidence published in a journal Epidemiological Studies A natural experiment that a population conducts on itself, probably without knowing they are doing so Look at large populations Leads to varying exposure The experimental factor the researcher is looking at Correlation The relationship between 2 associated things doesn't prove cause and effect Confounder A factor associated with some outcome that confuses or confounds the determination of true cause and effect Animal Studies Proves cause and effect Fast studies, cheap studies to conduct Human Studies Also known as clinical trials "gold standard of research" Far more complications and practical difficulties than animal studies Double Blind A study in which neither the researcher, nor the study subject knows which treatment the subject is getting Take a while to complete the study Cost much money, require much more time, than animal studies Major problem with this study: Compliance
Generalizability vs. Control Generalizability The degree to which one finding can be assumed to apply to some other group situation The question of whether what you found in rats applies to human Human studies have a high degree of generalizability Control The only difference between groups of subjects is the experimental variable Must conduct multiple studies Sources of Nutrition Information Safest source is scientific journals Nutrition Action is a reliable magazine Evolution of the Human Diet Changes in our diet over time have led to much disease that rarely existed Survey of Ancient Diets Ethnographic Records The study of indigenous human cultural and ethnic groups Hunter Gatherers Hunt animals, gather plants The diet depends on the environment Example of a culture is the Eskimo Meat based diet Example of a culture is the Ojibwa Wild rice based diet Agriculturalists Farming became more efficient Food Security in Traditional Societies Most modern Americans never miss a meal We have a high degree of food security Life hasn't been secure for most indigenous people Having originated in a particular geographic area, as in native people Food Shortage a Fact of Life Throughout Human Existence All cultures have experienced food shortages A universal part of the human condition Implications of PreHistoric Food Shortage for Modern Obesity
We have developed tools to deal with food shortage Taking surplus of food Putting on fat (Thrifty Metabolism) Comparing Ancient and Modern Diets Food Availability has Improved Industrial Revolution changed everything We now produce vast quantities of surplus food Supermarkets stock their shelves 50,000 new food products created each year ONLY the poor go hungry Diet Composition Has Changed Now contains more energy Most of our calories came from complex carbohydrates, mostly starch Now our diet contains more fat and sugar, less starch We eat less vegetables, and more meats A decline in the intake of fiber A decline in phytochemicals Meats today are different than meats in previous decades Now, more saturated fat Today, high protein diet= high fat diet Patterns of Health and Disease Our genes haven't changed, though our diet has Today, people die from different things than years ago Diseases of Poverty Different causes of death than in wealthy communities Mostly die of infectious disease and injury Die of micronutrient deficiency Diseases of Affluence Die of heart disease, cancer, stroke, and diabetes Caused by too much energy, fat, saturated fat, or salt AIDS and pneumonia/influenza are the only 2 infectious diseases in the top 10 causes of death in America Infectious disease is rarer here Chronic disease is caused by nutrient excess
Current health problems are caused by lifestyle factors Greatly reduced death from infectious disease and injury by improving public health and medical care *Are enough individuals in our society willing to make lifestyle changes?*
Nutri Sci 132 Chapter 2
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A Balanced Diet No substitute for a balanced diet Introduction Balance, moderation, and variety Core of nutrition recommendations The only fad that has never changed United States Department of Agriculture (USDA) Published by W.O. Atawater 1902 An Ecological Perspective The supply of nutrients and energy often limit the population size Human genes show some adaption to shortages over time Nutritional Requirements Essential nutrients Several chemicals our body requires Need to operate normally Must be present in the diet for good health Dietary Reference Intakes Gives specific recommendations for intake of each nutrient based on what the body needs Each nutrient has an optimal range intake Optimal range adequacy Intake of a particular nutrient that ensure the highest level of functioning Marginal deficiency Intake of a particular nutrient that is insufficient to ensure functioning. Functioning declines High intakes of some nutrients may cause toxicity Much more likely to occur if you use supplements Most common cause of childhood poisoning deaths is iron supplements Balance studies Try to find the level of intake that maintain a constant supply of nutrient to allow the body to function at its best Normal distribution Some individuals have needs at the extremes, but most have needs close to the middle Estimated Average Requirement (EAR) Sets the Recommended Dietary Allowance (RDA)
Nutri Sci 132 Chapter 2
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Designed to meet the needs of 97% of the population 2 standard deviations The mean of nutrient requirements in a population RDA is more than adequate for most people in good health Adequate Intake (AI) A value similar to the RDA, but without as much scientific evidence behind it Dietary Reference Intake (DRI) The RDA and the AI Upper Limit (UL) The maximum amount of a nutrient that an individual can safely eat Non toxic nutrients have no UL The Evolution of Dietary Recommendations Nutrient deficiency Most important nutrient problem Pellagra Niacin deficiency Affected most in southern states The Basic Four Gave minimum numbers of servings of various food groups This approach addressed proportionality Balance Adequacy was more important than balance Nutrient deficiencies mainly caused by poverty Chronic disease linked to intakes of fat, saturated fat, cholesterol, alcohol, and sodium Saturated fat A type of fat with particular chemical characteristics, generally found in animal products High intakes have been linked to heart disease Cholesterol A type of lipid linked to heart disease Dietary Guidelines for Americans Update the guidelines regularly Suggest Americans be more active, consume fewer calories, and make better food choices Guideline features 4 areas:
Nutri Sci 132 Chapter 2
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Balancing Calories to manage weight Foods and food components to reduce Foods and nutrients to increase Building healthy eating patterns MyPlate Developed to express the dietary guidelines in a way that could be used to plan meals Based on the concept that you can group together foods that contain similar nutrients Illustrates proportions Based on 2000 calorie diet
Fats and sugars aren't shown on myplate, but do exist in a diet Food Labels Food and Drug Administration (FDA) Regulates food labels ose is a carbohydrate, usually sugar all have low nutrient density relationship of nutrient content to energy content of a food Daily Value (DV) A value for daily intake based on a 2000 calorie diet Balance, Moderation, Variety Ensures proportionality and adequacy Prevents excess Helps prevent deficiency
Nutri Sci 132 Chapter 3
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Introduction Nutrients start outside the body Must be absorbed by the intestine The lining of our intestines protects us from our food Gut Gastrointestinal system Interacts with our food to send vital nutrients to the cells and organs Has to digest and absorb the nutrients, but protect us from harmful things in food Also called the GI Breaks down complex foods into simple components and absorbs these nutrients into the body 2 types of muscles in the gut that use 2 kinds of contraction peristalsis a rhythmic contraction of circular muscles surrounding the gut in such way as to move food forward high progesterone levels during pregnancy relax the muscles that cause peristalsis many pregnant women experience constipation because of this Laxatives stimulate peristalsis Segmentation Contraction of muscles surrounding the gut in such a way as to mix it with GI secretions Chyme The fluid mass of food in the intestinal lumen Sphincter keeps chyme from moving too quickly through the digestive tract Functional Organization of the Digestive System Uses 4 processes to get nutrients into the body Motility Secretion Digestion Absorption Motility Process of moving food through the gut Nerves transmit signals to the gut Stress can speed up motility Causes diarrhea Irritable Bowel Syndrome
Nutri Sci 132 Chapter 3
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Caffeine can speed up motility It affects the nervous system Esophagus The passage connecting the mouth and the stomach Gastric reflux Heartburn Pyloric Sphincter The valve controlling the flow of chime from the stomach into the small intestine Ileocecal valve Valve separating the ileum from the colon Secretion Synthesis and release of substances by cells in response to stimuli Denature To act on protein in such a way as to change its chemical and physical properties, so that its configuration or shape is different Protease Enzyme responsible for protein digestion Bile A secretion of the liver, stored in the gall bladder that emulsifies dietary lipid Emulsifier A substance that breaks fat droplets suspended in a waterbased medium into smaller particles, and keeps them in suspension Breaks fat into many smaller particles Digestion The chemical and mechanical breakdown of foods and of complex nutrient molecules into simpler components Peptides Short chains of amino acids Smaller than a protein Triglycerides Primary form of lipid in the diet Formed of three fatty acids on a glycerol backbone Monoglycerides Digested form of lipid in the diet Formed of three fatty acids on a glycerol backbone Churning
Nutri Sci 132 Chapter 3
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Muscular contractions of the gut Grind food and mix it with secretions Absorption Movement of nutrients from the intestinal lumen into the mucosal cells Lumen The interior of the gut Mucosa The cells of the gut lining Passive diffusion Absorption of nutrients that does not require the input of energy Driven by a concentration gradient Diffusion A movement of molecules from an area of high concentration to an area of low concentration Contrast with osmosis Concentration gradient A change in concentration of a substance over a distance Facilitated diffusion Movement of molecules across a membrane in the direction of a concentration gradient Aided by proteins embedded in the membrane Active transport Absorption of nutrients against a concentration gradient Requires the input of energy Endocytosis Absorption of large nutrient molecules involved the engulfing of the molecule by a portion of the cell membrane Antibodies A component of the immune system made from protein Foods Path Through the Gut Mouthesophagusstomachlivergallbladderpancreassmall intestinelarge intestinerectum The mouth Mechanical breakdown of food by chewing Mixes with saliva Contains amylase Enzyme responsible for starch digestion
Nutri Sci 132 Chapter 3
Contains small amounts of lipase Enzyme responsible for lipid digestion The esophagus Connects mouth to stomach Peristalsis begins The stomach Emotion is connected to digestion Churns food and mixes with digestive juices Breakdown of protein begins The Small Intestine Most chemical breakdown of food here Ten feet long 3 segments duodenum, jejunum, and ileum villi absorb nutrients microscopic fingers lining the surface of the intestinal lumen responsible for nutrient absorption greatly increase surface area of the intestine also called brush border Microvilli Hair like projections on the surface of the villi that increase surface area The Large Intestine Also known as the colon Clean up area Reabsorbs water Hosts large numbers of bacteria Can't digest fiber Transit time Amount of time food spends in passage through the gut The rectum Feces stay here until you eliminate them
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Nutri Sci 132 Chapter 4
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Introduction Carbohydrates used to be the limiting factor in a huntergatherers diet Best source of energy Come as various forms of simple sugars and complex carbohydrates Refined carbs have little to no nutrients An ecological perspective Begins with the sun Use photosynthesis to capture the sun's energy and store it in the chemical bonds of carbohydrates Classification and Occurrence Simplest carbohydrates are sugars Longest complex carb Starch Fiber Simple sugars joined by unbreakable chemical bonds Passes through the digestive tract relatively unchanged Carbohydrate often abbreviated CHO Simple Sugars Simplest and smallest carbohydrates Single and double sugars Monosaccharaides and Disaccharides Monosaccharaides 6 Carbon atoms arranged in a ring Glucose Six sided ring structure Fructose 6 Carbon atoms a 5 sided ring structure makes body fat Galactose Similar to glucose Part of lactose Double sugar found in milk Lactose intolerance
Nutri Sci 132 Chapter 4
People who can't break lactose apart Disaccharides Double sugars 2 monosaccharaides joined together by a chemical bond Sucrose one molecule of glucose and one molecule fructose Maltose 2 glucose molecules yeast can ferment this sugar to produce the alcohol in beer Other than lactose, carbohydrates come only from plants Complex Carbohydrates Strings of simple sugars form these Oligosaccharides Small strings of carbohydrate molecules Found in legumes and vegetables Can't digest, but bacteria in our colon can Can cause gas Glucose polymers Sports drinks contain these maltodextrins Polysaccharides Starch should supply most of our energy Glucose molecules joined by chemical bonds into very long strands Amylose Glucose chains are straight and have very few branches Amylopectin Glucose chains have many branches Used to thicken food Grains Best source of starches Glycogen Another glucose polymer similar to starch In the liver and muscles Important energy source during high intensity exercise
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Nutri Sci 132 Chapter 4
Dietary Fiber Cellulose Polysaccharide Made up of glucose chains The chemical bonds can't be broken Resistant to digestion Provides no calories Ruminant animals Cattle, sheep, and goats Capable of breaking down cellulose Insoluble fiber Doesn't dissolve in water Absorbs water Ex. Hemicellulose Give plant structural strength Ex. Lignin Acts like a fiber, but not a polysaccharide Body treats it as fiber Ex. Whole Grains Vegetables and fruits with edible seeds are good sources of insoluble fiber Soluble Fiber Dissolves in water Makes intestinal contents more viscous Different texture than insoluble fiber Ex. Pectin Used in jellies and jams Ex. Betaglucans Creamy texture of oatmeal Ex. Gums and mucilages Adds body to food Gives ice cream a smooth feel In low fat foods Oats, barley, rice, and beans are good forms of soluble fiber
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Nutri Sci 132 Chapter 4
Function of Carbohydrate Used as fuel 4 kcal/g indigestible carbs yield no kcals red blood cells and brain depend on carbs body uses carbs to make amino acids the building blocks of protein Adipose tissue Tissue that stores body fat Digestion and Absorption Digestive enzymes break down carbohydrates Enzyme names come from the carb they break down Digestion of carbohydrates Begin in the mouth Saliva contains amylase Chewing the food mixes with the enzymes Create broken down fragments Called dextrins Digestion stops in the stomach Stomach acid denatures salivary amylase Intestinal mucosa Line the intestinal tract Responsible for absorption of nutrients Lactose Intolerance Body needs to produce enzymes to be able to digest Most common enzyme deficiency Lactase insufficiency Causes lactose intolerance Lactose was not a common part of diet thousands of years ago Became popular when farmers started producing dairy products Different people react with different severity to lactase Blood Sugar Regulation Cells receive most of their carbs as glucose
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Nutri Sci 132 Chapter 4
Homeostasis The body maintaining a constant pH, temperature, and concentration of solutes Gluconeogenesis The process by which the body forms glucose from amino acids Glucagon Hormone that raises blood sugar Epinephrine Fight or flight hormone Response to stress or anger Insulin Released by the pancreas Lowers blood sugar by driving glucose into cells Blood Sugar Disorders Hypoglycemia Low blood sugar Most common type is postprandial After a meal Diabetes mellitus Disorder characterized by high blood sugar Signs of diabetes Polyphagia Excessive hunger Polydipsia Excessive thirst Polyuria Excessive urination The Glycemic Effect The ability of a carbcontaining food to raise blood sugar Simple sugars affect blood glucose levels the most Glycemic Index A measure of glycemic effect Effects of Added Sugar In processing foods, sugar is added
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Nutri Sci 132 Chapter 4
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Natural and added sugar are the same, however natural sugars bring added nutrients Humans have an innate preference for sweet food Average American consumes a 50 lb bag of added sugar each year High sugar intake reduced nutrient density A measure of the amount of nutrients found in a given number of calories for a particular food Sugar also promotes dental caries Known as cavities Caused by acid produced from carbohydrate by mouth bacteria Effects of Fiber Positive effects for our bodies Insoluble fiber keeps the digestive tract healthy Helps in peristalsis Reduces pressure in the colon Reduces transit time Helps prevent diverticular disease Out pouching of the intestine caused by high pressures due to a low fiber diet Soluble fiber Lower blood cholesterol levels Emulsify dietary fats during digestion Slow down absorption of carbohydrate after enzymes digest it Helps to control diabetes Sources Only found in plant foods Exception is lactose Recommendations 130 g/day body needs that amount to prevent ketosis when the body has to burn a lot of fat for energy
Nutri Sci 132 Chapter 5
Protein Introduction First nutrient recognized Highest recommended dietary allowance An Ecological Perspective Different from carbohydrate and fat Contains Nitrogen Essential to the structure of an amino acid Legumes Member of plant family capable of fixing nitrogen from the air Removes nitrogen from the air and renders it into a chemical form usable by plants Animals can't synthesize amino acids from nitrogen Amino acid Basic unit from which protein is made Consists of an amine group, carboxyl group, and side chains Structure Amino Acids 20 amino acids combine to form many proteins in our body composed of C,H,O, and N (sometimes S) amine an NH2 chemical group where the nitrogen is present Carboxyl A COOH chemical group Carboxyl and amine are joined by chains Amino acids are named by the chains Essential amino acids Body can't synthesize and must be consumed When nitrogen is left over, it's excreted through urea A nitrogencontaining compound Found in urine Peptides
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Nutri Sci 132 Chapter 5
A short chain of amino acids Joined together by peptide bonds A chemical bond joining 2 amino acids Dipeptidespolypeptides Ex of Polypeptide Insulin Many hormones are peptides Proteins Sequence Order in which amino acids appear in a protein, affecting its physical and chemical properties Proteins Veryyyyyy long chain of amino acids Collagen Primary protein in connective tissue Amylase Digestive enzyme which breaks down starch DNA Carries the sequence of amino acids in your genes Complex Structure Side chains Some attract and some repel each other The reason for amino acid shapes Similar to a phone cord The cord coils, just like protein, and strategically tangles itself Digestion and Absorption Proteins must be broken down into amino acids and short peptides Begin digestion in the stomach HCl denatures the protein Breaks protein down for protease Digestive enzyme which breaks down protein The amino acids are absorbed through mucosal cells They pass into the bloodstream Function
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Nutri Sci 132 Chapter 5
Structure Protein gives the body structure Ex. Muscle Carbohydrate is said to be proteinsparing Carbs act to preserve muscles If not enough carbs are eaten, muscle breaks down to supply blood glucose Gives shape to the bone Cell membranes have protein in them Constituents Blood transport proteins Carry nutrients and other substances in the blood Ex. Hemoglobin Lipoproteins Transport protein for lipids since lipids aren't water soluble Homeostasis Body tries to remain balanced Steady temperature, acidity, oxygen, solute concentration Maintain an acidbase balance
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The degree of acidity in a fluid, caused by an imbalance of hydrogen ions Maintain fluid balance Osmosis The movement of water from an area of low to high concentration across a permeated membrane Kwashiorkor Protein Energy malnutrition Movement of fluid from the blood stream to the abdominal cavity Regulation Enzymes Proteins that catalyze biochemical reactions Protein catalysts Control, regulate, and facilitate all biochemical reactions Facilitates the same reaction various times A small amount of enzyme is needed to react with a large amount of substrate
Nutri Sci 132 Chapter 5
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Material acted on by an enzyme Very specific MOST IMPORTANT REGULATORY SUBSTANCE IN THE BODY Hormones Messenger substances Systemic (whole body) effect Some hormones are peptides Ex. Insulin and growth hormones Nerve Impulse Transmission Precursor A substance from which another substance is formed 2 amino acids, tryptophan and tyrosine precursors for 3 neurotransmitters Neurotransmitter Substance used to bridge the gap of the nerve synapse and transmit nerve impulses Synapse Gap between nerve cells Nerve impulses bridge the gap with neurotransmitters Immunity Proteins are important in the immune system Antigens Foreign protein which trigger response by immune system When the body sees an antigen, it responds with antibodies Immune protein used to attack foreign protein Protein deficiency Leads to a decrease in the effectiveness of the immune response and increased risk of infection Energy Protein does get used as fuel 10% of our calories are protein protein as fuel is important when we run out of carbohydrates gluconeogenesis production of glucose from amino acids, used when carbohydrate sores are depleted Requirement Based on age and body weight
Nutri Sci 132 Chapter 5
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1215% of daily caloric intake protein deficiency is rare in the US more protein for athletes and pregnant women Sources Shouldn't eat too much Eat more beans, less fatty protein Quality Essential Amino Acids 9/20 amino acids are essential not synthesized by the body 11/20, some are conditionally essential can only be synthesized under certain conditions Assessing protein quality of a protein refers to how well it delivers the 9 essential amino acids Its effect on nitrogen balance Describes whether we are gaining or losing protein Limiting amino acid The amino acid in the shortest supply during protein synthesis, resulting in cessation of synthesis Measuring the effect on nitrogen balance Biological Value A measure of the degree to which an absorbed nitrogen is retained Nitrogen is used as a surrogate for protein BV=Nitrogen Retained Nitrogen Absorbed Chemical Score A comparison of the amino acid composition of a particular protein with a reference protein Protein DigestibilityCorrected Amino Acid Score Gives a realistic measure of proteins contribution to meeting needs Vegetarian Eating Different types of vegetarians Lactovegetarians Only eats plant and dairy products Lactoovovegetarians
Nutri Sci 132 Chapter 5
Plant foods, dairy products, and eggs Vegans Only eats food of plant origin Protein Complementarity Practice of combining 2 proteins to improve their amino acids proportions through mutual supplementation Protein Energy Malnutrition A deficiency of both protein and energy Caused by insufficient foods Caused by disruptions in the food supply Comes in 2 forms Marasmus Severe emaciation Kwashiorkor The bloated belly look Caused by abdominal edema Accumulation of fluid Excess Protein Intake High intakes of protein stimulate diuresis Urine formation by the kidney Causes a loss of calcium and may contribute to osteoporosis Can cause dehydration High protein intake is linked to heart diseases and cancer Because of the Saturated Fat
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Nutri Sci 132 Inter Chapter 6A
Alcohol Introduction More people consume alcohol than any other drug, with the exception of caffeine Alcohol is a food, as well as a drug An Ecological perspective Not a nutrient Can provide energy to the body Can be replaced by carb, protein, and fat Not essential Produced by microorganisms through fermentation of sugars Definition, digestion and absorption Ethanol Common drinking alcohol Very small, water soluble Simple 2 carbon molecule Absorption begins in the mouth, but most is absorbed in the stomach Contain congeners Nonalcohol substances present in alcoholic drinks 12 oz beer=8 oz malt liquor= 5 oz of wine= 1 shot Alcohol Metabolism Needs to be neutralized in the body Fate of ethanol Convert ethanol to acetaldehyde First product of alcohol breakdown Responsible for the flushing effect Alcohol dehydrogenase(ADH) Enzyme that converts alcohol to acetaldehyde Convert acetaldehyde to acetate Second product of alcohol breakdown Further converted to fat Alcohol Metabolism in Heavy Drinkers Microsomal Ethanol Oxidizing System Backup system for ethanol disposal used in heavy drinkers
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Nutri Sci 132 Inter Chapter 6A
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Gets rid of alcohol, but damages the liver Activates procarcinogens Substance made into a carcinogen by some biochemical pathway in the body Site of Alcohol Metabolism 9598% of blood alcohol metabolism takes place in the liver a much higher percentage of alcohol reaches the bloodstream in women Fat Production 7kcal/gram=alcohol almost as energy dense as fat excess calories from alcohol are stored as fat Blood Levels of Alcohol and Effects on the Brain Sex Differences affecting Blood Levels 25% of alcohol consumed by men never reaches the brain because it is oxidized in the digestive tract Higher BAC in women than men Rate Influences blood levels and the effect on the brain BAC legal limit is .08% Can't legally drive a vehicle if your BAC is above this For a woman, 3 drinks in 1 hour gets your BAC above this and for men it is 4 drinks in an hour Health Effects of Alcohol Consumption Hangover Result of overconsumption of alcohol Dehydration is part of a hangover Since alcohol is a diuretic, it increases urine production and the runs Liver Disease Acetaldehyde damages enzymes, liver structures Leads to liver disease Sixth leading cause of US deaths Women are at greater risk of this (cirrhosis) Heart Disease and Blood Pressure Moderate alcohol intake raises levels of HDL, the good cholesterol Reduces risk of heart attack 39 drinks per week resveratrol
Nutri Sci 132 Inter Chapter 6A
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found in red wine, reduces blood clots helps to prevent heart attack and stroke 25 drinks per week will raise blood pressure 510 points alcohol is most useful in those with low HDL who have normal blood pressure Cancer Acetaldehyde damages DNA First step in the development of cancer Alcohol calories displace calories form food with protective nutrients and phytonutrients The loss of these can allow cancer to develop Colon, breast, liver, prostate, pancreas, and stomach cancer risk is all raised by alcohol Weight Gain Increases the tendency towards abdominal fat, which has greater health consequences than anywhere else Athletic Performance Suffers Coordination, judgment, and cognitive ability all decline Alcohol interferes with recovery from exercise Low nutrient density Lowest possible nutrient density 7kcal/gram Fetal Alcohol Syndrome (FAS) Biggest known cause of mental retardation in the US Caused by alcohol consumption during pregnancy 1/100 births in the US are affected Teratogen Chemical that causes birth defects Addiction 15% of those who try alcohol become addicted Hits many receptors, not just 1 Addiction has a number of hallmarks Tolerance, withdrawal, loss of control, effects on life and family, unable to stop drinking, denial Social Problems Major contributor to crime, suicide, domestic violence, and more of all murders and car accidents are due to alcohol
Nutri Sci 132 Chapter 6
Lipids Introduction Lipids Substances soluble in organic solvents, but less soluble in water Hydrophobic "waterhating", repelled by water lipophilic fat loving fats and oils in food fats being solid and oils being liquid Americans eat way too much fat An Ecological perspective Most plants and fruits contain low to no levels of lipids Nuts and oilseeds (sunflower and sesame) are exceptions Avocado and olives are exceptions Most of the lipid in the environment comes from animals Carbon is present in lipids Organic compounds
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A complex chemical containing carbon in its structure. Often formed in a biological process Inorganic carbon in the form of carbon dioxide Carbon dioxide in the atmosphere has been on the increase Causes the planet to retain more heat Known as global warming Structure 3 kinds of lipid in the world triglycerides a type of lipid formed by three fatty acids arrayed on a glycerol backbone; Most fats occur in the triglyceride form phospholipids
Nutri Sci 132 Chapter 6
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a type of lipid similar to a triglyceride in which one of the fatty acids is replaced by a phosphoruscontaining compound sterols a type of lipid with a multiple ring structure, such as cholesterol Fatty Acids and Triglycerides triglyceride most of the lipid in our diet and body made from fatty acids a lipid form of a chain of carbon atoms, saturated by hydrogen atoms to varying degrees, with a methyl group on one end and a carboxyl group on the other Methyl Group CH3 Carboxyl Group COOH Valence The characteristic number of chemical bonds formed by a particular chemical element A sharing of electrons between 2 or more atoms Ex. Carbon= 4 Oxygen=2 Hydrogen=1 Saturated Fatty Acids(SFA) A fatty acid in which all of the carboncarbon bonds are single bonds; it is saturated with hydrogen atoms, that is, it contains all the hydrogen it can in its structure; found in animal products The carbon atoms each bond with 2 other carbon and 2 hydrogen atoms Each carbon forms 4 bonds Ex. Butyric (4C), Caprylic (8C), Stearic (18C) Straight line molecule Freezes more readily Freezes at a high temperature Makes saturated fats solid at room temperature Ex. Cell membranes are made of fatty acids
Nutri Sci 132 Chapter 6
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The melting point of these affect the fluidity of the membrane Membrane fluidity, in turn, affects the ability of that cell to remove cholesterol from the blood Having a lot of fatty acid membrane, makes the membrane less effective at removing cholesterol Saturated fats are the worse dietary contributors to heart disease Raises blood cholesterol Form animal fats Beef, pork, chicken, tropical oils(palm, palm kernel, and coconut) Fish is NOT saturated Monounsaturated Fatty Acids(MUFA) Replaced one of the single bonds with a double bond Still has 4 bonds Point of unsaturation A double bond in a fatty acid; not saturated by hydrogen atoms; more hydrogen could be added where the double bond could be split Lower freezing point than saturated fat Because less linear than saturated fat Takes a colder temperature to freeze MUFA's Oils are liquid at room temperature, but will cloud or get stiff if put in the refrigerator Ex. Olive oil, canola oil, sesame oil, walnut oil, avocado oil Lower blood levels of cholesterol Polyunsaturated Fatty Acids(PUFA) Many points of unsaturation, more than one double bond in the structure, found in vegetable fats Have 2 to 6 double bonds Most stay liquid in the freezer Ex. Omega3 polyunsaturate has its first double bond at the 3 rd carbon from the omega end Ex. An 18:3 fatty acid has 18 carbons with 3 double bonds Omega6 Polyunsaturates Most common vegetable oils
Nutri Sci 132 Chapter 6
Rich in linoleic acid (18:2) Essential fatty acid Lower both types of cholesterol in the blood Good in heart disease prevention Omega3 Polyunsaturates Fish oils Eicosapentanoic Acid (EPA) 20:5 Omega3 Docosahexanoic Acid(DHA) 22:6 Omega3 Fats in Foods Most of the time contain a mixture of all types of fatty acids Saturation and Environment Increasing saturation raises the melting point of a fat The less saturated a fat is, the more fluid it is Saturated fats get stiff at low temperatures For plants growing in cold climates, they are highly polyunsaturated Grow at temperatures just above freezing For plants growing in warmer climates, they can get by using saturated fats Membrane fluidity is not a concern Warmblooded animals Maintaining membrane fluidity is not a concern Animal fat can be saturated ColdBlooded Animals Fish Explains why highly unsaturated fats come from fish Triglycerides 98% of the time 3 fatty acids on a glycerol (alcohol) backbone Hydrogenation A process by which unsaturated fats become saturated;
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Nutri Sci 132 Chapter 6
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Hot hydrogen gas is bubbled through the fat; some of the double bonds break to form single bonds to be replaced by extra hydrogen atoms; can be carried through to any degree of saturation Ex. Shortening and margarine All double bonds are cis bonds ("same") When the cis bonds break, half will turn into trans bonds Transfatty acid Unsaturated fat in which one of the double bonds is in the transform, formed in partially hydrogenated fats hen double bonds break and reform; not found in nature Rancidity The off flavor caused by oxidation of lipids Become rancid as a result of peroxidation The process by which free radical oxygen attacks a double bond in a fat A very reactive species of oxygen, in which one of the electrons has been lost, creating an unstable electron shell, attacks lipids and other cellular substances Have an unpaired electron in their outer shell, which is not a very stable state Antioxidants Substances which protect cellular components against oxidation by reacting with free radical oxygen itself Phospholipids Replacing one of the fatty acids in a triglyceride with a phosphorouscontaining compounds Completely different uses in the body than triglycerides Small portion of our diet Our body synthesizes all we need In food Soybeans and egg yolks Added as emulsifiers Sterols Derived from and consist of a four ring structure
Nutri Sci 132 Chapter 6
Most famous is cholesterol
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Sterol with a multiple ring structure, synthesized by the body and used to manufacture steroid hormones and other substances; found only in animal foods No plant food contains cholesterol NO OLIVE OIL CONTAINS CHOLESTEROL Fat Substitutes Olestra A nonabsorbable fat substitute made by attaching fatty acids to a sucrose backbone Yields no calories Is a sucrose polyester 7 to 9 fatty acids on a sucrose backbone cant be digested vitamins get carried out on olestra which is bad Digestion and Transport Digestion and Absorption Since lipids are not water soluble, they must be encapsulated before going into the bloodstream Triglycerides are broken by lipase into monoglycerides and free fatty acids A single fatty acid attached to glycerol; formed by digestion of triglyceride Absorbed into the intestinal mucosal cells Sterols are absorbed unchanged Their dietary lipids are packaged into chylomicrons Large lipoprotein that transports lipid from the gut, delivering dietary triglyceride to body cells and cholesterol to the liver Protect lipids from the blood Bring dietary lipids from the guy and deliver triglycerides throughout the body Lipoprotein lipase Enzyme attached to artery wall that breaks down triglyceride from lipoprotein into free fatty acids and glycerol Very Low Density Lipoproteins (VLDL)
Nutri Sci 132 Chapter 6
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Lipoprotein formed in the liver which transports endogenous triglyceride to body cells. It also receives cholesterol from HDL for return to the liver Mostly triglyceride Formed in the liver Delivers triglycerides synthesized in the liver Split the triglyceride into free fatty acids and glycerol Return to the liver, while picking up High Density Lipoproteins(HDL) Lipoprotein which scavenges cholesterol from body cells and arterial plaque and transfers it to VLDL remnants for return to the liver and excretion; associated with a lower risk of heart disease Good cholesterol Scavenges cholesterol from cells and from your arteries, and carries it to VLDL remnants for transport back to the liver and excretion Cholesterol onn the way out of the body Low Density lipoprotein (LDL) Lipoprotein formed in the liver which transports cholesterol to body cells and arterial plaques; associated with a higher risk of heart disease Bad cholesterol Delivers cholesterol throughout the body, for vital uses and to clog your arteries Cholesterol on the way into the body Function Energy Fat supplies energy 9kcal/gram high energy density the amount of energy contained in a given weight or volume of a food; a food with high energy density contains a large amount of energy in a small amount of the food fat is a very concentrated source of calories Storage Form of Energy Fat is the source of energy we store Store triglycerides in adipose tissue Cell Membranes
Nutri Sci 132 Chapter 6
Consist mostly of phospholipids arranged in the lipid bilayer Double layer of phospholipids Eicosanoid Synthesis Lipid regulatory substances with a local effect; effect only the region of the body in which they were produced; made from longchained unsaturated fatty acids 20 to 22 carbons if made from Omega6 increase inflammation, promote blood clots, and constrict blood vessels If made from Omega3 Decrease inflammation, reduce blood clotting, and dilate blood vessels Essential Fatty Acids(EFA)
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Fatty acid necessary to the operation of the body but not capable of being synthesized by the body; must be present in the diet; the 2 essential fatty acids are linoleic acid and alphalinoleic acid Cholesterol Vital for our continued operation Raw material for steroid hormones, essential regulators of body function Lipids in Chronic Disease Dietary fats have been linked to heart disease and cancer Coronary Heart Disease A disease caused by atherosclerosis that results in a narrowing and thickening of arterial walls leading to insufficient blood flow to heart muscle and possibly resulting in heart attack Began to increase after WW1 Pathology The study of disease processes Atherosclerosis The thickening and narrowing of artery walls caused by the invasion of cholesterol Angina
Nutri Sci 132 Chapter 6
Chest pain caused by ischemia Insufficient blood flow Myocardial infarction
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Death of heart muscle from oxygen deprivation caused by blockage of arteries leading to the heart; a hear attack Stroke Brain damage from oxygen deprivation caused by blockage of arteries to the brain Etiology The study of the cause of disease Risk factors Uncontrollable risk factors Age The older you are, the more likely to have a heart attack Gender After menopause, women lose their estrogen Family History Controllable Risk Factors Smoking High blood pressure Obesity Sedentary life style Blood Lipids High blood levels of LDL mean a lot of cholesterol headed for your arteries High levels of HDL mean more cholesterol leaving the body Decreased risk of heart disease Dietary Factors that Increase Risk of CHD Saturated fats Transfatty acids Cholesterol Dietary Factors that Decrease Risk of CHD Monounsaturated fats Omega6 polyunsaturates
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Omega3 Fats Alcohol at good amounts Soluble Fiber Cancer The role of fat in the development in cancer is controversial Animal Studies Tell us that high fat intake leads to the onset of cancer Human Studies Correlation between national average intakes of fat and breast cancer; the more fat, the higher rate of breast cancer Sources Found in nuts and oilseeds Found in animal foods 34% of calories coming from fat in the American diet Requirements and Recommendations No minimum requirement Eat less saturated fat American diet Eats more saturated fat, lower vegetable intake, higher meat intake, lower fish intake, lower fiber intake
Nutri Sci 132 Chapter 7
Energy Balance and Obesity Introduction We have found that too much energy makes us fat An Ecological Perspective Individuals with a more efficient metabolism require fewer calories to maintain themselves Some stay thin regardless of what they eat Thrifty metabolism
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A genetically determined, energy efficient metabolism, requiring few calories for daily activities. In an environment of scarce food, such as found in prehistoric times, a thrifty metabolism allowed the storage of seasonally abundant food as body fat for use in times of food shortage. In a modern environment with a large surplus of calories, a thrifty metabolism contributes to the development of obesity. Ex. The Pima Indians of Arizona and northern Mexico The ability to put on body fat made life possible Today, over 50% are obese Overview of Macronutrient Metabolism Most body processes could be described as anabolic Pertaining to anabolism Those that create more complex chemical compounds for energy storage or synthesis of tissue Or as catabolic Pertaining to catabolism Body processes that break down complex chemical compounds for energy release of for tissue breakdown Anabolism The body building itself Anabolic processes Glycogen synthesis We can make glycogen from glucose or amino acids, but never from fat Protein synthesis Make protein from dietary amino acids Triglyceride synthesis
Nutri Sci 132 Chapter 7
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Any macronutrient eaten in excess will be converted into triglyceride and stored in adipose tissue Insulin is the hormone that directs anabolism Causing glucose and fat to move into cells from the bloodstream Catabolism The body breaking down itself Occurs during exercise, fasting, or physiological stress, when the body needs energy Adenosine triphosphate (ATP) High energy chemical compound used in the body to transfer energy from nutrients to various life processes Powers our movement Can produce ATP from blood sugar, muscle glycogen, body fat stores, or breakdown of muscle protein Which one you use depends on what you are doing Epinephrine, norepinephrine, and glucagon all direct catabolism In anaerobic metabolism, used in lower intensities, oxygen is used for energy production because the circulatory system is capable of supplying adequate amounts The only way the body can burn fat as fuel Fate of a Bowl of Oatmeal The starch in the oatmeal goes partly into replenishing muscle glycogen The protein in the oatmeal and milk is incorporated into muscle growth stimulated by yesterdays exercise Much would be stored in fat, if you weren't active the day before These are all anabolic processes After you eat, you take a short run Catabolic processes are put to work The remainder of starch and brown sugar from your oatmeal is taken up by muscle and burned to power your run Since energy expenditure is high during a run, the fat part of your breakfast is taken by muscle for present use Both carbohydrates and fat can be used as muscle fuel If you skipped breakfast and went for your run, your liver glycogen stores would be low You would rely mostly on fat energy Won't be able to run as fast or burn as many calories Fat only supports lower intensity exercise
Nutri Sci 132 Chapter 7
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Muscle tissue may be broken down to provide protein for gluconeogenesis Skipping meals tends to cause more muscle loss than fat loss Energy Conservation of Energy Energy can neither be created nor destroyed Energy can change form All biological energy comes from the chemical energy stored in food Which comes from photosynthesis Which comes from the sun 1000 calories=1 kilocalorie Efficiency of Conversion The efficiency of the conversion of energies varies Not all of the first form of energy becomes the second form Some energy is always lost as a third form, particularly heat Energy Balance Reflects the net flow of energy into and out of the body Reflects whether you are gaining or losing energy We can tell if we are gaining or losing energy if we are gaining or losing weight Energy balance= not gaining or losing weight Energy intake=energy expenditure Energy Expenditure We expend energy in 3 ways Basal metabolism Physical activity Thermal Effect of Food(TEF) Basal Metabolism Body processes involving involuntary activities only, such as breathing, heartbeat, and chemical reactions Excludes voluntary muscular activity Occur in lean tissue Fat requires very little upkeep compared to muscle and organ tissue Basal Metabolic Rate(BMR) Rate at which basal metabolism occurs Will vary from person to person, with some having a relatively slow or efficient metabolism
Nutri Sci 132 Chapter 7
Not under conscious control Chronic dieting lowers BMR Eating regular meals and building lean tissue can increase BMR Resting Energy Expenditure (REE)
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The day's total energy expenditure through basal metabolism only Makes up around 2/3 of total energy expenditure in the average person Physical Activity Energy expenditure through voluntary physical effort The more you weigh, the more calories you burn Thermic Effect of Food The energy cost of eating The energy expended digesting, absorbing, transporting, storing, and metabolizing nutrients 10% of food intake, a little higher for protein, a little lower for fat Estimating Energy Expenditure Estimating REE Estimating Energy Expended in Activity Activity Factors Expenditure by Activity and Body Weight Go hour by hour through your day More precise than activity factors Thermic Effect of Food 10% of calories consumed to derive this, add REE to physical activity take 10% of this total to get TEF Total Energy Expenditure The sum of REE, physical activity, and TEF Obesity Disease Consequences of Obesity More than a cosmetic problem Obesity leads to disease Heart disease, Type 2 diabetes, hypertension, cancer, stroke, and arthritis Shortens life spans Defining Obesity Simplest measure compares height and weight
Nutri Sci 132 Chapter 7
Or look at amount of fat on ones body Examine how the fat is distributed Simple Measures Height Weight Tables Originally developed by insurance companies Describe normal weights Newer versions have higher norms, reflecting higher weights in the population Body Mass Index A heightweight relationship used to assess obesity A BMI of greater than 25 is overweight A BMI of over 27 is obese Prevalence The number of cases of a condition in a given population or the proportion of the population suffering from that condition Relative Risk
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The increase in risk seen in a high risk group over that seen in the lowest risk group BMI fails to discriminate between fat and lean tissue Body Composition Percent body fat How much of our body weight is composed of fat Women tend to have higher body fat then men Body fat increases with age in adulthood Desirable range of fat Men=1020%, more than 25% is obese Women=1825%, more than 30% is obese Much harder to determine than BMI Underwater weighing Gold standard for body composition Measures the water displacement Skinfold calipers Measure the thickness of the fat layer under the skin in several locations Much easier and less expensive than underwater weighing Less accurate for extremely lean and obese people
Nutri Sci 132 Chapter 7
Body Impedance Analysis(BIA)
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A method of measuring body composition utilizing the fact that lean tissue, with a high water content, conducts electricity relatively well, while fat tissue, with a low water content, conducts electricity poorly. If a mild electric current is passed through the body, the body's impedance, or resistance to current flow, indirectly indicates its fat content Body Fat Distribution Subcutaneous fat The body fat depot found right under the skin Gives skin its thickness when you pinch it Visceral or Abdominal Fat Inside the abdominal cavity Under the abdominal muscles, inside the gut Intramuscular Fat Found interspersed within the muscle fibers Android obesity A pattern of body fat distribution in which most body fat is carried abdominally; the APPLE shape Higher risk of hypertension, Type 2 diabetes, and heart disease than gynecoid obesity; greater risk of health problems Gynecoid Obesity A pattern of body fat distribution in which most body fat is carried on the hips and thighs; the PEAR shape Prevalence and Distribution Over 60% of US adults are overweight Etiology Obesity is the products of genetics and the environment Twins are likely to be at similar body weight About 40% of obesity can be explained by genetics More than 20 human genes have been linked to obesity Set Point Theory
Nutri Sci 132 Chapter 7
The theory that ones body tends to gravitate to a particular weight The body resists change in weight Because as body weight changes, energy expenditure changes, as well Every pound is harder to lose than the last Governed by the hormone leptin Produced by adipose cells when they have reached a particular level of fat content Diminishes appetite and keeps cells from becoming fatter Adipose Tissue Body fat is stored in adipose tissue Reproduction Adipose tissue is essential for normal reproductive function in women When body fat drops below 15%, women often develop amenorrhea
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A cessation of normal menstruation caused by inadequate estrogen levels resulting from excessively low body fat. Causes bone mineral loss leading to weakened bones Female athlete triad The combo of low bone density, amenorrhea, and eating disorder sometimes seen in female athletes with very little body fat Can result in a 20 year old with the bones of a 70 year old Shock absorption Adipose tissue cushions internal organs from blows and absorbs shock Thermal insulation Adipose gives us insulation from the elements Those with low body fat are often cold Those with too much body fat often sweat Growth and Contraction of Adipose Tissue 2 ways for adipose tissue to grow an increase in the number of cells (hyperplasia) weight gain due to this tends to be harder to lose growing children tend to gain weight this way an increase in cell size (hypertrophy) these cells can more readily shrink
Nutri Sci 132 Chapter 7
adults tend to gain weight this way Body Weight Management Shortterm versus longterm weight loss: Need for a Lifetime Approach Long term failure for short term diets Many fad diets Defeat themselves by lowering metabolism Rapid weight loss is a loss of body water and lean muscle mass The only way to lose fat is to burn it off 1 pound=2700kcal can't sustain these long term diets because it messes up metabolism can't maintain odd diets for the long run water loss isn't permanent muscle loss lowers metabolism Failure Paths on the Road to Weight Control Fasting or Meal Skipping any reduction in food intakes triggers metabolic slowdown fasting and meal skipping will slow your metabolism you lower your metabolism the body reflexively responds to food deprivation with a binge when food becomes available the body overcompensates you train yourself not to eat you don't respond when your body says its hungry Very Low Calorie Diets Less than 1200 kcals per day Extreme restrictions using normal food Liquid diet Fail to provide any training in how to eat a sensible diet Not a lifetime proposition High Protein Diets Promote losses of water and lean tissue as well as fat, lowering metabolism, and producing rebound weight gain High protein diets are high in saturated fats Which promote heart disease Fad Diets No end to new diets
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Nutri Sci 132 Chapter 7
Anything that reduces intake below the level of expenditure will cause weight loss The question is how long you can maintain it Bariatric Surgery Of or pertaining to body weight Gastric bypass operations, stomach stapling, etc They reduce the size of the stomach or bypass it all together Drugs Only 3 drugs on the market see significant use for weight loss Sibutrimine Suppresses appetite and perhaps increase metabolism Phentermine Orlistat Blocks fat absorption Never use diuretics, laxatives, and amphetamines Only causes water loss Loses electrolytes Rebound constipation DON'T USE AMPHETAMINES Fundamentals: Eat Less, Burn More Energy intake=energy expenditure Then the way to lose weight is to go into negative energy balance Reduce intake, and increase expenditure Activity Increase energy expenditure 30 minutes of activity a day is plenty aerobic exercise increases heart rate direct caloric expenditure anaerobic exercise strength exercises raises metabolism Weight Loss and Metabolism Keep metabolism high By building muscle Preserve muscle mass during weight loss Weight loss must be fat loss to do any good to the body Eat when you are hungry TRY EATING EVERY 3 HOURS
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Nutri Sci 132 Chapter 7
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Avoid the dieters dilemma: the more weight you lose, the less energy you need, until your requirements get so low, you can maintain your weight by sniffing food Low Energy Density Foods Reduce energy intake By reducing energy from diet Energy density The amount of energy, or calories, carried in a measure of food With low energy density foods, you have to eat a lot to get a lot of calories Starch should be the largest component of your diet Behavior Change Eat when you are hungry Eat in a relaxed manner Have regular meals Make your life easier with limits Learn to cook Make cooking easy Don't clean your plate
Nutri Sci 132 Chapter 8
Eating Disorders Introduction Psychological, rather than nutritional disorders Deny bodies hunger cues Eating disorders represent a use of food to meet an emotional need Disordered eating becomes an eating disorder when it begins to interrupt one life Have the potential to be life threatening Can be biological or societal based An Ecological Perspective A phenomenon of affluent societies A way of dealing with food excess WE WANT TO BE THIN The Behavioral Continuum Satiety The sense of satisfaction or fullness after a meal that signals we've had enough Ways of eating Anorexia nervosa Characterized by starving behaviors, being underweight, and amenorrhea Binge Eating Disorder Characterized by binge eating, without any purging or restriction Suffer from obesity Bulimia Nervosa
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Characterized by binging and purging or other compensatory behaviors such as fasting or excessive exercise Use of laxatives, diuretics The Severity Continuum Skipping a meal on occasion isn't considered weird if it happens occasionally Disordered eating is very common in our culture Severe eating disorders may need professional treatment Etiology The origin of these psychological disorders lie in the dynamics of family, individual, and personality that drive all behavior
Nutri Sci 132 Chapter 8
Come from past experience and genetics Demographics Sufferers of eating disorders are primarily middle to upper class white females
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Nutri Sci 132 Chapter 8
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95% of those with eating disorders are female 90% are middle and upper class whites 80% come from highly educated households quite rare in developing countries 1 in 100150 women in the US have eating disorders 20% of college age women have an eating disorder in the US 74% of varsity female gymnasts have eating disorders Family Dynamics/Dysfunction Families of anorexia patients are more likely to be extremely controlling and not very nurturing or empathetic Obesity is often found in parents and siblings of people with bulimia Parents who expect their child to be perfect have higher chances of eating disorders Families in which the father is distant have a higher chance of eating disorders Predisposing Psychological Factors Depression and anxiety increase the chance of eating disorders A history of physical or sexual and sexual abuse increases the risk of eating disorders Bulimia nervosa and substance abuse shows a relationship Genetics A family pattern in eating disorders may be partly due to genetic factors Biological Neurotransmitters Lower levels of serotonin and norepinephrine have been found to be in people with anorexia and bulimia Levels of cortisol are higher Family Pattern First degree relatives of people with anorexia have an increased risk of anorexia and depression First degree relatives of people with bulimia have an increased risk of anorexia, depression, and substance abuse Emotional Eating Control Over One's Own Life Restricting food intake is a way to gain control of ones life May occur in anorexia since no one else can force you to eat Dealing with Stress Increased nutrient levels cause a pleasurable sense of wellbeing
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People may use this response to offset negative emotions encountered during stress, sadness, and frustration Binge eaters will remark that eating "numbs them out" Need for Acceptance A person with an eating disorder may feel they need to be thin to be accepted They can't be accepted for who they are The need to be good enough Food as Nurturing People often nurture themselves through eating Use eating as a way of nurturing themselves The practice of nurturing with food goes back to childhood Use food as a reward All or NothingGood/Bad ThinkersBingers (Dichotomous Thinking) Taking an all or nothing view doesn't help Need moderation Distraction A lot of emotional energy goes into weight and eating Can be a distraction from other personal issues Have to Eat Different than Alcohol and Gambling People with eating disorders say these conditions are harder to deal with than alcohol or drug abuse or gambling Avoidance of food isn't an option Body Image Distortion Distorted body image is particularly common with anorexia They see themselves as too fat Society PressuresThinness and Muscles Our society judges people by the way they look A lot of pressure to be thin for women Look like super models A lot of pressure to be muscular for men Look like action heroes Cultural Ideals of Men's and Women's Bodies The ideal comes form the media For many, cultural ideal is impossible How we should look from society is unrealistic
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Women pick the ideal body to be thinner than what men would choose their ideal women to be You can be your own worst enemy SportSpecific Body Type Demands Gymnastics, ballet, and distance running often lead to eating disorders for women Wrestling for men Less fat makes better athletes, yet eating disorders cause the deterioration of lean mass Lean mass= power, so there is a loss of power Eating Disorders in Men Underreported and growing in existence Men want to be "buff" Muscle dysmorphism The drive to get big muscles Summary of Etiology Include personal and external factors Depends on the person Characteristics, Complications, and Treatment Starving: Anorexia Nervosa Definition and Types Results in amenorrhea Cessation of normal menstrual cycles Restricting type of anorexia Starve themselves Pure starvation Bingeeating/purging type of anorexia Binging and purging behaviors History First medical description in 1689 in England Nervous consumption Very similar definition as is today First blip of anorexia= 19101925 Flapper era Second blip of anorexia= 1960s "Twiggy" first of the supermodels
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sparked a movement of supermodels and the want to be thin that we are in today causes 3% of women today Characteristics Affects your judgment Very distorted perception of reality Tend to be perfectionists Hold themselves to high standards High functioning goal oriented people Tend towards OCD Starving Strategies "push peas around he plate to look like their eating" may become vegetarians Age of Onset Early adolescence As young as 11 or before Course of Disorder Constant unless intervention occurs People with anorexia will not get spontaneously better on their own If not treated, 30% will die from starvation The risk of mortality is 510% Complications Starvation brings many complications Amenorrhea Results from extremely low body fat Since body fat is necessary for the metabolism of estrogen, insufficient levels of fat will cause the cessation of menstruation Causes loss of bone mineral density Chances of premature osteoporosis are extremely high Emaciation and muscle wasting occurs when the body converts proteins to carbohydrates through gluconeogenesis Hypothermia Low body temperature due to lower basal metabolism caused by meal skipping and low carbohydrate intake May spur the development of lunago
Nutri Sci 132 Chapter 8
Fine, downy hair development over the body in anorexia to retain heat Weakness and fatigue Low intakes of electrolytes Adequate levels of these are needed to maintain heartbeat With low levels, cardiac arrhythmias can result in death Loss of heart rhythm Can lead to heart failure Treatments For anorexia Inpatient therapy, hospitalization Refeeding is involved Death can result if done too rapidly Dietician must be involved Cognitive behavioral therapy for all disorders Counseling by a psychotherapist Long term therapy Drug therapy like antidepressants may be involved Good success when done well Binging: Binge Eating Disorder Binging without purging or intake restriction Definition A particular type of overeating Binge The consumption of a large amount of food in a discrete period of time, usually considered to be about 2 hours Not able to stop what they are eating during this time Relationship to Obesity and Depression Most recently recognized of the eating disorders Large overlap between binge eating and obesity Binge eaters are likely to be obese Not all obese people binge Similar overlap between binge eating and depression Binge eating disorder affects about 15% of college women Biology of Binging
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Nutri Sci 132 Chapter 8
Many factors drive people to binge, but aren't the direct cause Boosts levels of serotonin Reduces anxiety and depression by calming and relaxing Carbohydrates in the meal provoke the release of insulin Drives the transport of tryptophan, an amino acid, into the brain It's the precursor of serotonin Characteristics Primary characteristic is high or increasing body weight Leads to obesity Induced by stress Produce social isolation Since binges are often done in private Obsessive and depressive thoughts Age of Onset Later than for other eating disorders Early adulthood Complications Largely those of obesity Chronic heartburn and bloating Chronic diarrhea and constipation Increase metabolism and excess body fat will retain heat Lead to hyperthermia High body temperature Decrease in insulin sensitivity Lead to Type 2 diabetes Treatment Usually outpatient and focuses on psychotherapy Nutrition education Behavior modification Exercise program to help lose weight and reduce stress Antidepressant medication No Middle Ground: Bulimia Nervosa Brings the worst of both worlds Definition and Types Recurrent binges and inappropriate attempts at compensation
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Nutri Sci 132 Chapter 8
Binges are like those in Binge eating disorder Purging Type Selfinduced vomiting, laxative abuse, and diuretics and enemas Nonpurging type Fasting and excessive exercise History First description in 1959 Increased with the media on the want to be thin In wealthier countries 910% of college women Pendulum Swings Between Binging and Starving (Purging) Feast to famine Restricts food intake (starve themselves) Then a rebound from hunger occurs Binge occurs Characteristics Rapid eating of food with little chewing Feelings of depression, frustration, or worthlessness after the binge Feel as if they are watching someone do this (dissociation) Increased incidence of substance abuse Course of Disorder Late adolescence to early adulthood Intermittent over years Comes and goes High achieving people like anorexics Complications Enlargement of parotid glands Stomach acid can cause deterioration of teeth A dentist usually diagnoses bulimia Stomach acid can cause ulcers if the esophagus, pharynx, and mouth Reflexive vomiting Automatic after eating Laxative abuse can cause rebound constipation
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Nutri Sci 132 Chapter 8
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Electrolyte imbalance Can lead to death Treatment Outpatient Multidisciplinary Medical care and psychotherapy Cognitive behavioral approach Nutrition education Substance abuse treatment Antidepressants The Female Athlete Triad Energy restriction, high training loads, and binges Athlete may abuse exercise Obsessive and compulsive tendencies in athletes lead to high risk of eating disorder Also the ability to be disciplines, dedicated, and the intense pressure to do well Treatment is similar to other eating disorders Coaches are involved as well Recommendations Helping Someone with an Eating Disorder Need to give support Someone to talk to and feel they aren't being judged "you are perfect the way you are" How to Get Care A psychotherapist, a dietician, and a physician Hospitalization is required for all if severe enough Insurance for this issue is lacking Prevention Lies in healthy families Parents must be involved in children's lives Child needs to feel loved, valued, and secure Don't use shame Sports No athlete should be told they are fat
Nutri Sci 132 Chapter 9
Sports Nutrition and Energy Metabolism
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Nutri Sci 132 Chapter 9
Introduction Respiration
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General term for energy release The process of producing energy from fuels using oxygen and producing carbon dioxide and water This kind occurs in the cells The intensity of the exercise dictates the rate at which the body must release energy Maximal oxygen consumption or VO2max The maximum amount of oxygen that can be supplied at ant instant in an individual training increases this aerobic the condition of producing energy through processes that require oxygen having sufficient oxygen to do so can use fat and carbohydrates to produce energy anaerobic the condition of producing energy through processes that do not require oxygen not having sufficient oxygen to produce energy through other processes can use carbohydrate, but not fat to produce energy glycogen carbohydrates stored in the muscle and liver cells the intensity and duration of the activity determine the body's choice of fuels An Ecological Perspective Exercise performance depends on our ability to store and use fuel The keys to optimal performance Training Affects the supply of oxygen and fuels to muscle cells Nutrition Affects the availability of fuels to the cells CHO is the optimal fuel for muscles Only fuel the body can use for high intensity anaerobic exercise The body can only store limited amounts of carbohydrates
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Exercise Basics Nutrition and Exercise Exercise increases energy expenditure Means you can eat more Eating more means taking in more nutrients Exercise is important for weight control Maintains weight loss Increases energy expenditure during the activity Increases basal metabolism during the rest of the day by building or maintaining muscle mass Body uses fat stores to produce this extra energy Exercise helps to regulate appetite When sedentary subjects increase activity, they decrease their energy intake Slowly their energy intake matches their energy expenditure Energy intake=energy expenditure Exercise helps to prevent chronic disease Increases levels of HDL cholesterol Aerobic exercise increases the muscles demand for oxygen Increases the density of capillaries in the muscles Increases the supply of oxygen Exercise helps prevent other chronic diseases Type 2 diabetes and cancer People who exercise regularly are less likely to have breast and colon cancer Weight lifting strengthens bones to reduce osteoporosis risk Exercise in older adults Builds the strength to do everyday activities Exercise has psychological benefits Help decrease depression and anxiety Increase vitality Improved sense of well beingbetter food choices The Training Principle Fitness develops as the body adapts to the physical stress of regular exercise During rest the body adapts by compensating or overcompensating for the stress Fitness increases as the physical stress increases and the body continues to adapt Need rest
Nutri Sci 132 Chapter 9
Overtraining
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A physical state of staleness, tiredness, and even deconditioning caused by too much training and too little recovery, possibly exacerbated by inadequate nutrition Types of Exercise Aerobic Exercise Challenge and develop the ability of the cardiovascular system to deliver oxygen to the muscles These exercises increase the demand for oxygen This demand increases breathing and heart rate Heart rate correlates with energy expenditure The faster the beat, the faster you burn calories Ex. Endurance sports(running, skating, etc.), soccer(energy in spurts) Strength Exercise Isolates muscles and works them intensely Strength exercise is done until the muscle can go no longer Builds strength Resistance exercise builds strength but do little for the cardiovascular system Builds muscle mass Ex. Weight training, calisthenics, yoga, plyometrics A strength training method characterized by a rapid stretch of the muscle prior to contraction Consideration in Planning Training Programs Stress, rest, adapt Consideration in Aerobic Training Programs FIT principle Frequency, intensity, time Frequency Training stress must be applied regularly 34 times a week Intensity Heart rate is used to measure intensity Heart rate increases as energy expenditure increases Anaerobic threshold
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The level of exercise intensity at which anaerobic energy production becomes necessary and lactic acid begins to accumulate in the muscle Maximum heart rate=220your age Time Body needs continuous exercise to develop cardiovascular fitness 2030 minutes is considered a minimum Consideration in Strength Programs Technique and Safety Resistance exercise can have a major impact on strength When done incorrectly, can cause injuries Frequency and Recovery 24 times per week for weight training and resistance exercise Progression Fitness is achieved by progressive applications of stress Ten percent rule Increase workouts by 10 percent at a time Dealing with Injury Prevention Warm up Begin the activity slowly Stretch after Recovery Use active rest Movement maintains metabolism and encourages blood flow to the injury, allowing for faster recovery Correct the problem with proper equipment Reduce the activity that caused the injury by 50% try a different type of exercise that uses difference muscles Good nutrition Lifelong Exercise Commitment Exercise needs to become a priority and part of ones everyday routine Find what works for you Purpose Find an activity that has other useful purposes Ex. Ride bike or walk to work
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Recreation Exercise for fun Find an activity that you enjoy Ex. Skiing, skating, biking People who exercise for fun are most successful at maintain lifelong exercise IntraChapter Summary Exercise requires energy Aerobic pathways require oxygen and are used when the demand for oxygen is low enough that the circulatory system can deliver it in adequate amounts Anaerobic pathways are used when demands for oxygen outstrips the ability of the circulatory system to supply it Fitness is the cumulative adaption to progressively applied stress Aerobic training=Frequency, intensity, time Strength training= technique safety, frequency, recovery Energy for Exercise The three macronutrients all supply energy for exercise 3 systems for converting these macronutrients into useful energy immediate energy system a system that releases energy stored in creatine phosphate for rapid maximal muscle contraction of very short duration anaerobic glycolysis the process that splits glucose into pyruvate and releases energy to ATP and NADH Aerobic metabolism A series of processes that begins with the conversion of pyruvate to acetyl CoA, proceeds to the citric acid cycle, and ends with the electron transport chain Aerobic metabolism produces NADH, H+, FADH2, ATP, CO2, and water Requires oxygen as the final electron acceptor Energy balance is the net flow of these energy sources into or out of the body Positive balance means the body is accumulating energy Weight gain Negative balance means the body's energy stores are being depleted Weight loss Energy Balance
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Amount of energy going into and out of the system is bigger in active people Losing rate requires being in negative energy balance Better to create negative energy balance by increased energy expenditure and slight decreases in food intake Energy and ATP Adenosine triphosphate ATP powers all the processes in the body ATP transfers energy from nutrients to energydemanding processes such as muscle contraction and biosynthesis ATP Consists of an adenosine molecule with three inorganic phosphate groups attached Simple phosphate groups incorporated into ATP and other molecules and then released in order to transfer energy As ATP splits into adenosine diphosphate and one inorganic phosphate, stored energy is released from the broken phosphate bond High energy chemical compound used to transfer energy from nutrients to various life processes ATP is very short term storage The body maintains very little ATP at one time The body carries much creatine phosphate High energy chemical compound used to store and release energy in the immediate energy system Body only has enough CP for 315 seconds of max effort Nicotinamide adenine dinucleotide(NAD) An intermediary, formed from the vitamin niacin that transfers high energy electrons released from nutrients as they are metabolized to ATP Flavin adenine dinucleotide(FAD) An intermediary, formed from the vitamin riboflavin, that transfers high energy electrons released from nutrients as they are metabolized to ATP Very similar to NAD FAD and NAD are derived from B vitamins
Nutri Sci 132 Chapter 9
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FAD from riboflavin NAD from niacin Carbohydrate Can be used to produce energy using aerobic or anaerobic processes Energy production using carbohydrate Begins with anaerobic glycolysis Produces energy without using oxygen Carbohydrate from food is broken down to glucose in the body During glycolysis, glucose breaks into two smaller molecules and releases energy Further breakdown requires oxygen The further the breakdown, the more ATP The limiting factor in aerobic energy production is the amount of oxygen that can be delivered to the cells Anaerobic Glycolysis Splits the glucose molecules in half Into 2 pyruvate molecules A 3 carbon molecule formed from glucose in anaerobic glycolysis If oxygen isn't available, pyruvate can be converted to lactate A 3 carbon molecule formed from pyruvate Excess lactate is shuttled to the liver to be converted back to glucose via the Cori cycle The process by which accumulated lactate is shuttled to the liver to be converted back to glucose and returned to the muscle Provides a means to deal with the pyruvate that accumulates during anaerobic glycolysis Uses no oxygen Only produces limited amounts of energy When lactic acid accumulates in muscle cells, it lowers the pH The main source of energy during shorter, more intense events lasting between 30 seconds2 minutes Aerobic Metabolism When sufficient oxygen is available
Nutri Sci 132 Chapter 9
1st, Conversion of pyruvate and coenzyme A to acetyl CoA Coenzyme A
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A compound formed from the B vitamin pantothenic acid that is combined with pyruvate to create acetyl CoA, which then enters the citric acid cycle Pantothenic acid A B vitamin used to form coenzyme A, which activates pyruvate for entry into the citric acid cycle Acetyl CoA Formed from pyruvate and coenzyme A Allows pyruvate to enter the citric acid cycle 2nd, acetyl CoA enters the citric acid cycle the pathway by which acetyl CoA combines with oxaloacetate and, through a series of reactions yields NADH, H+, FADH2, ATP, CO2, and finally returns to oxaloacetate, ready to start the cycle again with another acetyl CoA also known as Krebs Cycle also known as TCA Cycle electron transport chain a series of carrier molecules that transfers the high energy electrons of NADH and FADH along to AATP their energy is stored in ATPS phosphate bonds until the electrons are passed to oxygen so that they combine with hydrogen to form water Glucose Sources for Muscle Muscle glycogen is the preferred source of fuel for exercise Body spares muscle glycogen for when it is needed most After about 15 minutes of working out, use of blood glucose increases dramatically Working muscle can cause blood glucose to drop Body maintains blood glucose in 3 ways Liver converts glycogen into glucose and releases it into blood Dietary carbohydrate is absorbed from the gut into the bloodstream
Nutri Sci 132 Chapter 9
Breaking down body proteins by gluconeogenesis
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The process by which the amino group is removed from amino acids and they are converted to glucose Last resort Preserve Muscle with Carbohydrate Carbohydrates spare body proteins and preserve muscle Adequate carbohydrate intake is important for building muscle Brain can only use glucose, unless extreme fasting Training with depleted liver glycogen reserves is likely to result in loss of muscle protein through gluconeogenesis With time, this promotes weight gain Dietary carbohydrates also promote muscle growth Eat carbohydrate food right after exercise Better Performance with Adequate Carbohydrate Liver and muscles store more glycogen when the diet includes adequate carbohydrates The more glycogen that is stored improves performance in 2 ways: Longer time to exhaustion during exercise High carb diets extend endurance and increase the time it takes to reach exhaustion High carb intake increases glycogen reserves The higher the glycogen reserves, the higher intensity achieved in a workout for a longer time More Consistent Training High carb diet helps prevent the chronic fatigue caused by depletion of glycogen stores Glycogen stores are replaced quickly due to high carb diets Eat or drink before exercise in the morning The Glycemic Index A measure of how quickly a carb is digested and absorbed from the gut Food with a lowGI contain starch Foods with a high GI contain sugars Foods with high GI get food into the blood stream more quickly Before exercise, foods with lower GI are better Slowly released into the bloods stream to last throughout exercise During and after exercise, high GI foods are the best Foods containing sugar are good at these times Fat
Nutri Sci 132 Chapter 9
Less versatile fuel than carbohydrate Cant be used for anaerobic metabolism Body uses fat to spare its carbohydrate reserves Energy production From Fat Fat is oxidized in the mitochondria of the cell
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The cell structure where most of the reactions in the aerobic production of energy from fat, carb, and protein take place Carnitine acts as a shuttle to transport fatty acids across the mitochondrial membrane Produced by the body in adequate amounts Also sold as a supplement Metabolism of Fat Begins in mitochondria with betaoxidation Fatty acids are shortened two carbon atoms at a time and combined with coenzyme A to form acetyl Co for entry into the citric acid cycle Fat produces carbon dioxide and water Fat requires oxygen to produce energy Fat is the main fuel used for extended lower intensity exercise Fat Burns in a Flame of Carbohydrate The citric acid cycle begins and ends with oxaloacetate If carbohydrate stores are depleted, the body runs out of pyruvate When carbohydrate isn't available, acetyl CoA is diverted into chemicals called ketone Bodies Produced when fat is used for energy because of insufficient dietary carbohydrate Ketone bodies build up in the blood, making it acidic, causing ketosis Training Increases Fat Use Training increases the body's ability to burn fat Training also increases the body's ability to deliver oxygen to the cells, so it can produce energy via the aerobic metabolism of both fat and carbohydrate at higher intensities As you train, the percentage of calories that comes form fat increases for a given level of intensity Fat cant completely replace carbohydrate as a fuel
Nutri Sci 132 Chapter 9
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Fatty acid sources for muscle Muscle draws fatty acids from the bloodstream to use as fuel All fat depots can be used during exercise Don't eat a meal high in fat before exercise Fat Storage Most of the body's energy is stored as fat Fat is preferred for storage of calories Fat Burning and Weight Loss Working muscle near a fat deposit will not burn fat close to that particular area Weight loss recommendations often include working out at lower intensity to maximize weight loss Higher intensity exercise burns more calories per hour Exercise is the only way to increase fat utilization Protein Protein and the Citric Acid Cycle Amino acids can enter the same pathways of aerobic metabolism to yield energy as do carbohydrate and fat Some amino acids can be stripped of their nitrogencontaining component, the amino group, and their carbon skeletons enter directly into the citric acid cycle, though at different points The carbon framework of an amino acid The amino group that is removed from the amino acid is made into ammonia and then urea by the liver and is excreted by the kidneys in urine Gluconeogenesis Glucogenic amino acids Amino acids which are made into pyruvate and then into glucose through gluconeogenesis Amino acids that can be made into acetyl CoA are called ketogenic amino acids Amino acids which are made into acetyl CoA for entry into the citric acid cycle, but which cannot be used in gluconeogenesis to make glucose Gluconeogenesis traps energy in the bonds of glucose so that it can be released when needed
Nutri Sci 132 Chapter 9
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Gluconeogenesis uses energy Protein and Muscle Building Foods high in protein are associated with strength and power Eating protein doesn't stimulate muscle growth, exercise does Exercise increases protein requirements Protein Requirement 1.21.6g/kg of body weight 1015% of calories as protein Adequate Protein from Normal Diets Most people in America already eat enough extra protein Problems with Excess Use of Protein as a Fuel High protein diets have a diuretic effect and stimulate urine production Problems such as dehydration and loss of calcium from bone, extra stress on kidneys which leads to early kidney failure Macronutrient Composition Body can use all the macronutrients for fuel Some combinations work better than others Carbohydrate is necessary for higher intensity exercise Fat is important for lower intensity exercise Protein is important as a back up source of carbohydrate and to build muscle fibers Endurance performance peaks when the diet contains 2030% of calories from fat, 10 15% from protein, 5570% form carbohydrate Most Americans eat 34% fat IntraChapter Summary The body uses ATP to capture the energy from all the macronutrients using a variety of pathways Anaerobic glycolysis releases energy form glucose by splitting it into 2 pyruvate molecules If adequate oxygen is available, this pyruvate is converted into acetyl CoA Micronutrients Not as dramatic uses in exercise Muscle Synthesis, Preservation, and Repair Zinc Needed to make new cells Composed of 100 enzymes and other proteins Regulate the expression of genes that control tissue growth and injury repair
Nutri Sci 132 Chapter 9
Sources Meat, seafood, dairy products, whole grains, and seeds Excess may inhibit the immune system and reduce absorption of other minerals Better to obtain zinc from foods rather than supplements Potassium Major positively charged intracellular ion
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Inside cells Vital for muscle contraction and condition of nerve impulses Potassium can be lost in sweat, so exercise during hot weather exercise can increase potassium needs Inadequate potassium intake can impair performance and may cause muscle cramping Sources are fruits and vegetables, sports drinks, and juices Excess potassium is excreted by the kidneys Iron Component of myoglobin a protein that is the muscle's equivalent to hemoglobin transfers oxygen from the blood to the muscle cell for use during exercise required for muscle building plays a role in energy metabolism as a component of the electron transport chain deficiency limits hemoglobin synthesis and causes microcytic anemia the red blood cells are smaller than usual sources are meat, fish, and poultry, dark leafy greens, beans, dried fruits, fortified cereals, and other plant foods excess intakes of iron can cause oxidative damage and even death key component of hemoglobin deficiency limits hemoglobin synthesis and causes microcytic anemia red blood cells are too small sources are meat, fish, and poultry, dark leafy greens, beans, dried fruits, cereals excess intake can cause oxidative damage and death Chromium Helps insulin bind to its receptor on the cell and is important for synthesis of muscle protein and glycogen
Nutri Sci 132 Chapter supplements 9
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Chromium may increase strength gains from training and may increase lean body mass Sources are unprocessed foods and whole grains High doses may be linked with kidney and chromosome damage Pyridoxine (Vitamin B6) Necessary for protein synthesis Important in muscle repair and growth Needed for synthesis of nonessential amino acids Deficiency limits development of lean tissue Found in many foods High doses may cause neurological damage Helps synthesize hemoglobin Deficiency results in inadequate amounts of hemoglobin for red blood cell production Vitamin C Involved in the synthesis of collagen The primary protein found in connective tissue Deficiency causes poor wound healing and deterioration of connective tissue Sources are fruits and vegetables Intakes higher than 2000mg/day may cause GI upset and contribute to oxidative damage to cells The body can become dependent on high doses so the body can develop scurvy The disease caused by a deficiency of Vitamin C Water soluble Also an antioxidant Enhances absorption of plant forms of iron Deficiency can contribute to the development of iron deficiency Antioxidants Protect muscle and red blood cells from oxidative damage Caused by free radicals A highly reactive species of oxygen or other substance capable of damaging cell components and contributing to cancer and heart disease Large amounts of free radicals are created during aerobic exercise Aerobic exercise increases the body's need for antioxidants
Nutri Sci 132 Chapter 9
Also enhances the body's ability to dispose of free radicals Vitamin E Fat soluble vitamin Significant antioxidant Deficiency can cause hemolysis A breakdown of red blood cells Good sources include seeds, nuts and seed oils, and some vegetables Best source is wheat germ Excessive intake may interfere with absorption of vitamin K Selenium Component of the glutathione peroxidases A group of antioxidant enzymes Sources are meats, seafood, and whole grains Extremely high doses can lead to selenium toxicity Causes loss of hair and nails Carotenoids Vegetables contain about 500 different carotenoids Best known is betacarotene Body uses this to make Vitamin A Sources are fruits and vegetables, especially the more colorful ones Orange fruits and vegetables get their color from betacarotene High levels of carotenoids can contribute to oxidative damage Excessive intakes can only happen by supplements Erythropoiesis
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Formation of erythrocytes, more commonly known as red blood cells Important during exercise to transport oxygen from the lungs to working muscles and other organs Anemia The condition of having inadequate red blood cells to transport sufficient amounts of oxygen Folate Important for cell division
Nutri Sci 132 Chapter 9
Used to produce new red blood cells Necessary for the formation of the new DNA If insufficient folate, cell division can't occur This causes macrocytic anemia
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A type of anemia in which red blood cells are too few and too big, caused by folic acid deficiency Sources are dark leafy greens, beans, and orange juice High intakes may mask symptoms of vitamin B12 deficiency Vitamin B12 Regenerates folate after it has been used by the cell Deficiency would produce a secondary deficiency of folate Sources are only animal produces Energy Release Several B vitamins are involved in the release of energy from Carbohydrate, fat, and protein Deficiency of these B vitamins cause exhaustion, weakness, fatigue, lethargy, and a loss of coordination Niacin Used to make NAD+, the electron acceptor that transfers energy to ATP in the electron transport chain Sources are high protein foods High doses can cause severe flushing and even liver damage Riboflavin Made into FAD, another electron acceptor in the transfer of energy to ATP using the electron transport chain Best sources are milk and dark leafy greens Pantothenic Acid Used to make coenzyme A Sources are many foods Thiamin Used as the basis of TPP Important for nerve and muscle metabolism Good sources are foods high in protein and whole grains Bone Repair Overuse can cause stress fractures
Nutri Sci 132 Chapter 9
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Calcium Adequate intakes help to achieve high bone mineral density Good calcium intakes are important in children Sources are dairy products and dark leafy greens Excessive intakes may reduce absorption of other nutrients Phosphorous Found combined with calcium in bone Abundant in the food supply Vitamin D Necessary for absorption of calcium from the gut This deficiency creates a calcium deficiency During growth periods, inadequate amounts of vitamin D cause a malformation of bone known as rickets Sources include fluid milk and the sun Excessive intakes can be toxic Vitamin K Helps maintain the protein matrix of bone Low Vitamin K contributes to bone fractures Sources are green leafy and cruciferous vegetables Vitamin A Excessive intakes may weaken bone Nutrient dense Foods Best Approach Nutrient dense foods are the best approach to proper intake of vitamins and minerals A varied diet should provide adequate amounts of micronutrients in balanced proportions Exercise increases the requirement for some micronutrients and increases the overall calorie needs Fluids and Electrolytes Maintaining fluid balance during Exercise The body's main method of losing heat is sweating Sweat uses the body's heat to evaporate, so as sweat evaporates, the body cools Large sweat loss can cause dehydration Thirst and Dehydration Dehydration impairs performance and could lead to death A dehydrated body cant cool itself with sweat, so the body overheats, called heat stroke Dehydration causes loss of electrolytes
Nutri Sci 132 Chapter 9
Dehydration may acute acute kidney failure Dehydration is dangerous because it happens slowly The body can lose sweat faster than it can absorb it from the gut You were dehydrated before you were thirsty "Drink Early, Drink Often?" don't wait to get thirsty before you drink hyponatremia
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the condition caused by drinking too much water and having a low concentration of sodium in the blood because of it can cause fatal heart arrhythmias safest to drink an electrolyte drink rather than just water Cold Weather Cold air is very dry and significant amounts of water can be lost through the lungs Monitoring Hydration Status Urine color and volume If urine is light in color, with volume and frequency near normal, you are probably getting enough water If urine is dark and volume is low, drink more Some vitamins will color urine Electrolytes Molecules that are separated into electrically charged atoms Sodium and potassium are the most important electrolytes that are lost in sweat Failure to replace these causes hyponatremia and hypokalemia Low concentration of potassium in blood Hyponatremia or hypokalemia only occur during exercise that lasts for more than 2 hours under hot conditions Replacement Water and electrolytes must be replaced During Exercise Exercise at an intensity of greater than 70% of max delays stomach emptying so that fluids are absorbed into the body more slowly Mode of exercise also affects absorption Runners have a harder time digesting and absorbing food than cyclists Carbohydrateelectrolyte Replacement Drinks
Nutri Sci 132 Chapter 9
Best way to replace fluids during prolonged exercise The carbohydrate in the drink slows the onset of fatigue Sports drinks are helpful because they contain isotonic amounts of sodium and potassium A fluid with solute concentrations equal to those found in body fluids Intake of too much of an electrolyte can cause problems during exercise, such as cramps and nausea, because water follows salt Sport drinks contain isotonic amounts of sodium, potassium, and sugar Soft drinks are hypertonic
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They contain more sugar than bodily fluids They make fluid flow into the gut from the bloodstream and can even trigger diarrhea from excess water in the gut Cold water is absorbed more quickly than warmer water, but satisfies thirst more quickly, and may reduce intake Practical Considerations A variety of flavors can encourage you to drink more Cold or cool beverages is easier to drink in hot weather Diuretics Drugs that stimulate urine formation Common diuretics include caffeine and alcohol Cause loss of fluid in urine After Exercise Sports drinks are unnecessary after exercise Alcohol and Exercise Performance Alcohol cant be used as fuel for muscles Alcohol impedes recovery from exercise by inhibiting glycogen synthesis Alcohol is a diuretic and may contribute to dehydration IntraChapter Summary Recommendations Athletes need more servings from each food group Athletes should eat carbohydrates and low fats Carbohydrate intake should be consistent and distributed throughout the day to maintain high glycogen stores PreExercise Meal
Nutri Sci 132 Chapter 9
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High in carbohydrate and easy to digest Any complex carb Bread, oatmeal, rice, pasta, potatoes, bananas, or cereal high glycemic index pre workout low GI throughout the day, high GI right before a workout no fatty or fried foods pre exercise During Exercise of More than One Hour Duration High intensity 2530 grams of carbohydrate (100120 calories) every 2040 minutes high GI carbs during exercise sugar 512 ounces every 1520 minutes Post Exercise Within about 1520 minutes of finishing, eat something that contains a fairly high GI carbohydrate Sport drink, soda, fruit juice After exercise, eat or drink 1gram of carb/kg of body weight Eat within 30 minutes2 hours a meal after exercise The Principles of Feeding Carbs are usually the limiting nutrient in exercise
Nutri Sci 132 Chapter 10
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Introduction The human body is mostly water An Ecological perspective Life depends on water Clean water is a diminishing resource Lading cause of infant mortality worldwide is infant diarrhea, from lack of clean water Body Water Content and Distribution Content Adults=5060% water Infants are more Blood plasma is 90% water Muscle is 72% water Fat tissue is 2035% water Higher water content means more lean mass and lower percentage of body fat Body Fluid Compartments 2 compartments intracellular water inside cells 60% of body water extracellular water outside cells includes plasma, interstitial fluid(the space between cells in the body), tears, synovial fluid(pertaining to the joints), and gastrointestinal secretions 40% of body water Water retention Sodium Eating more salt=retain more fluid Makes you puffy and bloated from the extra fluid Diuretics Decreases the volume of fluid in the body Functions and Properties of Water and Electrolytes Water and electrolytes are inseparable Water: The universal Solvent No other fluid will dissolve as many different substances as water will
Nutri Sci 132 Chapter 10
Water is where all our biochemical reactions occur Dissolved Solutes in Water Electrolytes When dissolved in water, these salts break into ions These ions are electrolytes that conduct electricity Pure water cant conduct electricity, but water with electrolytes can Role of Electrolytes in nerve and muscle Electrolytes send nerve impulses, maintain fluid balance, muscle contraction, and regulation of heartbeat Sodium is the major extracellular cation(+) Potassium is the major intracellular cation Chloride is the major anion() in both intra and extracellular depolarization a decrease in electrical charge in a nerve cell which triggers a nerve impulse action potential the electrical signal that makes up a nerve impulse repolarization
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an increase in electrical charge in a nerve cell after a nerve impulse has been transmitted Acid Base Balance Temperature Regulation 98.6 degrees internally regardless the weather outside at 108 degrees, brain proteins denature 92 degrees, people often lose consciousness 85 degrees and below, one could die Water has a High Specific Heat Takes more heat to raise the temperature of the body a specific amount Constriction and Dilation of Blood Vessels Blood flowing through the skin will lose heat to the environment Constriction of the blood vessels will decrease that heat loss while dilation will increase it
Nutri Sci 132 Chapter 10
Perspiration As sweat evaporates from the skin, it pulls heat off with it, using latent heat of vaporization
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The energy required to change water from liquid to gas Participant in Chemical Reactions Energy Metabolism Water is a product of energy metabolism Aerobic metabolism of glucose and the beta oxidation of fat both yield water and CO2 as products Hydrolysis The splitting of a water molecule in order to provide charged fragments to combine with charged fragments of some other molecule Transport Medium Blood Plasma 90% water Waste Removal Once in the kidneys, the blood is filtered to remove wastes and put into the urine Urine is loaded with water Lubricants The moving parts of the body are lubricated by water Tears keep the eyes clear Saliva helps you swallow Gut secretions move food through the digestive tract Synovial fluid lubricates the joints Fluid Balance Thirst Signal for not having sufficient fluid in the body Experience this when your fluid level has dropped by less than 1% of body weight Elderly and sick people lose a sense of thirst Absorption Simple for water Moves across the intestinal wall 80% of water is absorbed in the small intestine 98% of the water you consume is absorbed
Nutri Sci 132 Chapter 10
Fluid Shifts Maintain Intra and ExtraCellular Volumes Osmosis
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The movement of water from an are of low solute to high solute concentration across a membrane Water follows salt Protein and electrolytes keep fluid in the bloodstream and in the cells Excretion Routes of water loss Lost via the kidneys as urine Lost from the skin as sweat Lost through the GI tract in feces Lost through the skin and lungs in insensible losses Losses not sensed or noticed as they happen Typical Losses Typical=23 liters per day Regulation of Fluid and Electrolytes Dehydration When we lose too much or don't drink enough water Infant Diarrhea Major cause of infant mortality worldwide Death can occur with losses of water equivalent to 1020% of body weight Due to dirty water Treatment is oral rehydration therapy Given water with electrolytes and glucose Hot Weather Exercise Sweat losses due to overheating cause an electrolyte depletion Can result in heat stroke Drink electrolyte replacement drinks Hyponatremia Low blood sodium Hypokalemia Low blood potassium
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Both can cause cardiac arrhythmias and even death OverHydration This occurs in an overdone attempt to stay hydrated The increased fluid volume will dilute blood concentrations of sodium and potassium Sources Don't count on caffeinated beverages to keep you hydrated Alcohol and caffeine are both diuretics, which won't keep you hydrated Milk is nutrient rich Electrolyte Balance Dangers of Electrolyte Loss Prolonged poor intake will lower blood levels of electrolytes Extremely low levels of potassium can result in cardiac arrhythmia Sodium deficiencies are rare Electrolyte Imbalance in Eating Disorders Low intakes of electrolytes can be due to anorexia and bulimia Cardiac arrhythmias is most often the immediate cause of death in both of these diseases Excess Intake and Urinary Excretion Kidneys regulate electrolytes In the short term, extra electrolytes aren't a problem Hypertension High blood pressure Hypertension definedsystolic and diastolic Blood Pressure Top number=systolic Contracted phase of heartbeat Bottom number=diastolic The residual pressure between heart contractions High blood pressure is defined as being greater than a systolic over diastolic of 140 over 90 (140/90) Contributing Factor to Heart Disease Hypertension contributes to atherosclerosis and congestive heart failure Atherosclerosis The process of cholesterol buildup in the arteries leading to coronary heart disease Congestive Heart Failure Higher diastolic blood pressure forces greater pumping effort from the heart Eventually, the heart cant keep up with the need and blood pools in the veins
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Sodium and High Blood Pressure High sodium intake increases blood pressure In the US, 70 year olds have higher blood pressure than 20 year olds In developing countries, these 2 groups have the same blood pressure Other Minerals Involved in Hypertension DASH Study Compared 2 dietary approaches to a control group The control group consumed 4 servings of fruits and vegetables per day which put their potassium and magnesium intakes in the 75th percentile, their calcium intake was the 25th percentile The combination group had an intake of 10 servings of fruits and 2.7 of vegetables putting their intakes high for potassium, magnesium, and calcium in the 75 th percentile Results 7 mmHg drop in systolic pressures and about 3 in diastolic for people in the first group 11 mmHg drop in systolic pressures and 6 in diastolic for the second group 129/84 is now borderline hypertension Other Dietary Factors in Hypertension Obesity and alcohol consumption Both increase blood pressure Dietary Sources of Electrolytes Salt doesn't naturally come from food, potassium and magnesium come from fruits and vegetables Processing foods flips the ratio of high potassium to sodium to high sodium to potassium Americans eat double the recommendation for salt The taste for salt is a learned preference Recommendations 11.5 Liters per 1000kcals of energy expenditure is pretty good
Nutri Sci 132 Chapter 11
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Introduction Vitamin C was the first controlled experiment in the field of nutrition Lind gave one group seawater, one group vinegar, one group cider, one group citric acid, and one group a spiced laxative in 1740 to try to find the cure for scurvy Cider group showed some improvement, but the citrus fruit group recovered Carried lime juice This was the first application of scientific nutrition to improve health An Ecological Perspective Overview of the Micronutrients Vitamins Beginning of 20th century Water Soluble Vitamins If you consume too many water soluble vitamins, they excrete through the kidneys and urine Hard to develop toxicity with water soluble vitamins Body doesn't store water soluble vitamins Easy to develop deficiencies Vitamin C and the B Vitamins ( thiamin, riboflavin, niacin, folic acid(folate), vitamin B 12(cobalamin), vitamin B6(pyridoxine), biotin, and pantothenic acid) Fat Soluble Vitamins Can't be excreted through urine, so you store excess, which can lead to toxicity Deficiencies develop slowly Vitamin A is the most common deficiency in the world and US Vitamin A (retinol), D, E, and K Minerals Product of cosmological processes Get minerals from meats and vegetables and fruits Competition for Absorption Iron, calcium, zinc, lead, and copper all are divalent cations Ions with a double positive charge If a large amount of one, it creates a deficiency of the others because of competition to get into the blood stream Large calcium supplements frequently suppress iron and zinc absorption Diets poor in iron and calcium make you more vulnerable to lead poisoning
Nutri Sci 132 Chapter 11
Bioavailability
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The degree to which a nutrient is absorbed in digestion 275% of minerals get absorbed 95% of macronutrients get absorbed factors that affect bioavailability fiber and phytic acid(phosphorus compound found in grains and legumes) reduce the absorption of minerals oxalic acid(a compound found in some fruits and vegetables) greatly reduces absorption of calcium tannins(found in tea) reduce iron absorption acid increases the solubility of minerals bad for the elderly Meat, fish, and poultry increase the absorption of plant forms of iron from 2 to 20% Major Minerals Needed in relatively large amounts Bone Components= Calcium, phosphorus, magnesium Electrolytes= sodium, potassium, chloride Sulfur Trace Minerals Present in much smaller quantities Iron is the most common mineral deficiency Iron, copper, zinc, iodine, selenium Micronutrient Roles in Body Function Essential in synthesis and repair of tissue, preventing oxidative damage, synthesis of blood cells, release of energy from macronutrients, and in bone maintenance and repair Tissue Synthesis, Preservation, Function, and Repair
Nutrient Function Deficiency disease Deficiency symptoms Over consumption Best sources
Zinc
Enzymes, cell division
Poor growth, wound healing, slow maturation, immune response
Impaired immune response
Meat, fish, poultry, nuts, seeds
Nutri Sci 132 Chapter 11
Iron Oxygen transport(hemog lobin), enzymes, nervous system Microcytic anemia(small RBCs) Anemia, low energy Oxidative damage
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Meat, fish, poultry, dried fruit, dark leafy greens, whole grains, beans
Vitamin B12 (cobalamin)
Activates folate, myelin sheaths
Pernicious anemia
Large red blood cells, neuropathy
Animal products
Folate (folic acid)
Activates B12, DNA synthesis, spinal column development in pregnancy
Macrocytic anemia(RBCs don't divide so they are large RBCs)
Large red blood cells, neural tube defects (pregnancy)
Masks B12 deficiency
Dark leafy greens, vegetables, beans, orange juice
Potassium
Electrolyte, nerve, muscle contraction, hearth rhythm
Weakness, heart arrhythmia
Fruits and vegetables
Sodium
Electrolyte, nerve, muscle contraction
Weakness, heart arrhythmia
hypertension
salt
Calcium
Bone, teeth, muscle contraction
Bone demineralization
Milk products, dark leafy green vegetables
Chromium
Insulin binding
rare
Whole grains
Pyridoxine (vitamin B6)
Amino acid synthesis, neurotransmitter
Anemia, neuropathy
neuropathy
Widely distributed
Nutri Sci 132 Chapter 11
, hemoglobin synthesis
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Vitamin C
Collagen synthesis, antioxidant, immune response, enhances iron absorption
scurvy
Poor wound healing, bruise easily, scars reopen, teeth fallout
Fruits/vegetabl es, dark leafy greens, peppers, potatoes, kiwi, citrus
Vitamin A (retinol)
Vision, cell differentiation Antioxidant (betacarotene)
Night blindness, blindness, keratosis
Liver toxicity, headaches, bone pain, bone fractures, birth defects
Orange and yellow fruits and vegetables, dark leafy green vegetables, milk
Antioxidants Protect us against oxidative damage Free radical oxygen Attacks vital cell components Singlet electron Unpaired electron Highly unstable Oxidative damage affects cell membranes, cell proteins, LDL, vision, and DNA
Nutrient
Function
Deficiency Disease
Deficiency Symptoms
Overconsumption
Best Sources
Nutri Sci 132 Chapter 11
Vitamin C Collagen synthesis, antioxidant, immune response, enhances iron absorption scurvy Poor wound healing, bruise easily, scars reopen, teeth fall out Fruits/
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vegetables, dark leafy greens, peppers, potatoes, kiwi, citrus
Vitamin E
antioxidant
Anemia, lowered immune response
Wheat germ, whole grains, seed oils (corn, soy)
Vitamin A (retinol and Carotenoids)
Vision, cell differentiation, antioxidant(beta carotene)
Night blindness, blindness, keratosis
Liver toxicity, headaches, bone pain, bone fractures, birth defects
Orange and yellow fruits and vegetables, dark leafy greens, milk
Selenium
Antioxidant enzymes
Oxidative damage, impaired immune response
Whole grains
Prooxidants
Beta carotene could lead to cancer; iron and zinc could lead to toxicity if taken in pill form
Fruits and vegetables for carotenoids
Nutri Sci 132 Chapter 11
Erythropoiesis Process of the formation of erythrocytes, or red blood cells Anemia Insufficient red blood cells to transport an adequate amount of oxygen Ferritin Storage protein for iron Transferrin Transport protein for iron These two above help to determine if there is an iron deficiency
Nutrient Function Deficiency Disease Deficiency Symptoms Overconsumption
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Best Sources
Folate(folic acid)
Activates B12, DNA synthesis, spinal column development in pregnancy
Macrocytic anemia
Large red blood cells, neural tube defects (pregnancy)
Masks B12 deficiency
Dark leafy greens, vegetables, beans, orange juice
Vitamin B12(cobalamin)
Activates folate, myelin sheaths
Pernicious anemia
Large red blood cells, neuropathy
Animal products
Vitamin B6(pyridoxine)
Amino acid synthesis, neurotransmitter, hemoglobin synthesis
Anemia, neuropathy
neuropathy
Widely distributed
Iron
Oxygen transport(hemoglobin), enzymes, nervous system
Microcytic anemia
Anemia, low energy
Oxidative damage
Meat, fish, poultry, dried fruit, dark leafy greens, whole grains, beans
Nutri Sci 132 Chapter 11
Vitamin C Collagen synthesis, antioxidant, immune response, enhances iron absorption scurvy Poor wound healing, bruise easily, scars reopen, teeth fall out Fruits/
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vegetables, dark leafy greens, peppers, potatoes, kiwi, citrus
Energy Release Many key participants in metabolic reactions are made from B vitamins and minerals B vitamins are used to make coenzymes, which activate enzymes
Nutrient Function Deficiency Disease Deficiency Symptoms Overconsumption Best Sources
Phosphorus
Energy production (ATP/ADP), bone
rare
abundant
Niacin
Energy release(NAD)
Pellagra(niacin deficiency)
Dermatitis, diarrhea, dementia, death
Liver and kidney toxicity
Protein foods, whole grains
Riboflavin
Energy release (FAD)
Inflamed mouth and tongue, dermatitis
Milk, dark leafy greens
Pantothenic Acid
Energy release (coenzyme A)
rare
ubiquitous
Thiamin
Energy release (TPP)
Beriberi (disease caused by deficiency of thiamin)
Weakness, exhaustion, lethargy
Protein foods, whole grains
Biotin
Energy release
rare
ubiquitous
Nutri Sci 132 Chapter 11
Chromium Insulin building rare
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Whole grains
Iodine
Thyroid hormone (thyroxine)
Goiter, an enlargement of the thyroid gland
Thyroid enlargement
Seafood, idized salt, dairy products
Nutri Sci 132 Chapter 11
Bone Repair Growth Begins as cartilagereplaced by hydroxyapatite( a compound of calcium and phosphorus) in a protein matrixbone grows Matrix provides form while mineral gives it strength Growth takes place at the epiphyseal plates(the ends of long bones) Remodeling After growing ends This is the continual process of bone formation and restoration Osteoblasts Cells that build bone Lay down protein matrix and mineral Osteoclasts
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Dissolve bone and matric, releasing minerals into the blood stream Calcium Most of the calcium in the body is in bone Gives bone strength Muscle contractions involve calcium, as does blood clotting, enzymes, and cell signaling Blood Levels of Calcium Tightly Regulated Tightly controlled with in 3% up or down of normal Hormonal Control of Blood Calcium Concentration If blood concentrations of calcium are low Parathyroid hormone(PTH) is released from the parathyroid gland Acts on the kidney to increase vitamin D, which acts on the mucosal cells of the intestine to increase their absorption of calcium. If more calcium is absorbed from the GI tract, blood concentrations will rise to their normal level Also stimulates osteoclasts Cells that break down bone and matric, releasing calcium into the bloodstream, and raising blood calcium concentration Half of dietary calcium is absorbed
Nutri Sci 132 Chapter 11
If blood concentrations of calcium are high Less than of dietary calcium is absorbed Thyroid gland releases calcitonin
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Hormone from the thyroid gland that lowers blood calcium Stimulates the osteoblasts, which form new bone, taking up calcium from the blood, and lowering blood calcium This calcium is stored in the bone for when it is needed Factors Affecting Calcium Status
Nutrient Function Deficiency Disease Deficiency Symptoms Overconsumption Best Sources
Phosphorus
Energy production (ATP/ADP), bone
rare
abundant
Vitamin D
Calcium absorption, bone metabolism
Rickets, bone deformation in growing children
Bone malformation in children
Over absorption of calcium, calcium deposits
Sun exposure, fluid milk, fish oils
Vitamin K
Blood clotting, bone metabolism
Defective blood clotting, bone fractures
Dark leafy green vegetables
Vitamin A
Vision, cell differentiation, antioxidant(beta carotene)
Night blindness, blindness, keratosis
Liver toxicity, headaches, bone pain, bone fractures, birth defects
Orange and yellow fruits and vegetables, dark leafy greens, milk
Vitamin C
Collagen synthesis, antioxidant, immune response, enhances iron absorption
scurvy
Poor wound healing, bruise easily, scars reopen, teeth fall out
Fruits/ vegetables, dark leafy greens, peppers, potatoes, kiwi, citrus
Nutri Sci 132 Chapter 11
Magnesium enzymes
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Whole grains, vegetables
Nutri Sci 132 Chapter 11
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Amenorrhea Caused by low levels of body fat Can result in bone mineral losses Necessary for the metabolism of estrogen Low levels of estrogen allow bone demineralization Osteoporosis Progressive weakening of the bones, leading to a loss of height and to fractures The Imbalance at the Heart of Osteoporosis Osteoporosis stems from an imbalance between the processes of bone formation and resorption from bone Contributing Factors to Osteoporosis Menopause Less Vitamin D Poor Calcium Intake Prevention of Osteoporosis Build good bone mineral reserves early in life Maintain good reserves later in life Good Bone Health Balanced diet with adequate intakes of calcium and Vitamin D Weight bearing exercises Micronutrient Sources Nutrient dense foods best approach to adequacy Whole foods Foods in their natural state Fortified foods Foods with added nutrients Supplements Nutrient obtained in purified and concentrated form, and consumed as a pill or drink rather than from a food in its natural state Food sources of Major Nutrients Vitamins Whole grains, vegetables, fruits, and protein Provitamins (precursors)
Nutri Sci 132 Chapter 11
Vitamin A and niacin both can be obtained from precursors Fat Soluble Vitamins Vitamin A (retinol) Retinol The active form of vitamin A Carotenoids A group of chemicals, some of which, particularly betacarotene, are precursors of retinol Betacarotene
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Common plant precursor of retinol Vitamin D The one vitamin that can be synthesized by the human body in which we more properly call it a steroid hormone than a nutrient Vitamin E Mostly found in seeds, such as grains, in the germ, or living, part of the seed Vitamin K Found in green vegetables, and especially green leafy vegetables The greener, the more vitamin K Water Soluble Vitamins Vitamin C C is the fruit and vegetable vitamin BVitamins Whole grains and protein foods Minerals Whole grains, vegetables, protein foods, dairy products, and fruits More in animal protein Sodium Salt Chloride Salt, sodium chloride, is also the primary source of chloride Potassium Diametric opposite of sodium In fruits and vegetables
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Calcium Dairy products Phosphorus Second present in the body after calcium Everywhere Magnesium Found in vegetables and whole grains Iodine Found in food grown in iodine rich soils Iron Heme iron Meat, fish, and poultry Nonheme iron Found in plant foods, dried fruit, dark leafy greens, beans, and whole grains Zinc Meat, fish, and poultry, nuts and seeds Fortification Adds nutrients to foods in which they were not originally present Not regulated, except in enrichment Vitamin D is added to milk and Iodine is added to salt Effects f Processing on Micronutrient Content Causes nutrient loss Effects of Cooking Heat Damages Sensitive Nutrients Vitamin C and Thiamin are sensitive to heat Cooking Makes Some Nutrients More Available Minerals are stable when cooked Micronutrient Status Causes of Deficiency Dietary Inadequate Intake Diminished Bioavailability Accelerated Losses Iron Electrolytes Increased Needs
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Deficiency Diseases Treatment of Deficiency Nutritional supplements Whole foods Abundant Nutrients Rarely experience deficiency with some of them Toxicity Role of Supplements Best for known deficiencies Get enough iron in pregnancy
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Nutri Sci 132 Chapter 12
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Introduction Phytonutrients Called phytochemicals Non nutrient components of plant foods that have physiological effects on humans Lower cholesterol, reduce the risk of cancer, lower blood pressure Not technically nutrients Not essential in the diet If failed to consume, we don't develop deficiencies Low intake over a period of time can increase your likelihood of cancer or heart disease An Ecological Perspective Fundamental cell function becomes deranged without them, resulting in cancer and other disease Plant Foods and Cancer 2/3 of cancers can be attributed to the environment most of these 2/3 of cancer are due to smoking not smoking is the biggest single thing you can do to reduce your risk of cancer second thing you can do to reduce risk of cancer is eat a diet rich in fruits and vegetables Fruits and Vegetables 128/156 studies shows that fruits and vegetables protect against cancer eating fruits and vegetables can cut your cancer risk in half Protective list of fruits and vegetables Lettuce, leafy greens, onions, carrots, cabbage family, citrus, broccoli, potatoes, raw and fresh fruits and vegetables Nutrients as Protective Mechanism Vitamin A as Protective Factor Retinol has a role in cell differentiation, which is the process by which newly formed cells mature Retinol is protective against cancer in cell culture studies Retinol deficiency in animals get more cancer Blood levels of retinol are not correlated with cancer risk in humans Vitamin A Precursors as Protective Factor Produce contains betacarotene which is a precursor of retinol Betacarotene hypothesis Beta carotene protects against cancer without conversion to retinol
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beta carotene is a powerful antioxidant and blood levels of beta carotene correlate with cancer risk AntiOxidant Hypothesis
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Antioxidant compounds such as beta carotene protect the body from oxidative damage that could lead to cancer Oxidative damage is caused by free radical oxygen, an oxygen atom with an unpaired electron Oxidative damage of DNA can lead to cancer Antioxidants quench free radicals React with the free radical and donate an electron They stop the oxidative rampage The antioxidant blocks the DNA damage, preventing cancer Vitamin C and E are powerful antioxidants Carotenoids Less than 1/3 of the US vitamin A intake comes from carotenoids 500 carotenoids to be found in nature only half a dozen are used as a precursor to retinol (beta carotene is the significant source) yellow and orange fruits and vegetables are excellent sources of beta carotene example of carotenoid is lutein and lycopene found in highest concentration in the blood Beta Carotene Trials Chemoprevention Prevention of cancer by use of phytochemicals Finnish study which looked at 29000 male smokers; 4 treatment groups ( betacarotene pill, vitamin E pill, both, or a placebo); antioxidant supplements DON'T help in preventing cancer Conclusion and Parable Supplement form of antioxidants don't prevent cancer Phytonutrients Diet rich in tomatoes lowers risk of prostate cancer 3000 such anti carcinogens of various strengths have been identified Carcinogenesis The process by which cancer develops Carcinogens The chemicals that damage DNA and initiate cancer development Occupational Exposures Particular cancers would show up in certain industries Asbestos=lung cancer vinyl chloride= liver cancer
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These exposures are much less common today Pollutants Pesticides and herbicides, auto emissions, and groundwater contaminants contain carcinogens Food Carcinogens Nitrites/ nitrosamines Added as a preservative(bacon) and in food processing(beer) Nitrates are converted to nitrosamines in the body Levels of these in foods has decreased a lot in the past few years Pickling, Spoiled Food Stomach cancer has declined rapidly The decline is thought to be as a result of food safety With refrigeration today, less spoiled food is eaten Eating a lot of pickled food can cause cancer, but with fresh food today, there is no need for much pickling Molds Make nerve gas from mold toxins Ex. Aflatoxin Cancer rates in rural areas are much lower, except liver cancer Peanuts are vulnerable to aflatoxin Carcinogens Naturally Present in Foods Bracken fern and sassafras contain natural carcinogens, but aren't eaten a lot Food Carcinogens do not Appear to be Responsible for Many Cancers Today, worker and food safety has improved Tobacco is the only widespread exposure to a single carcinogen ThreeStage Model of Carcinogenesis Normal cellinitiated cell cancer cell tumor Initiation, promotion, progression Normal Cells Apoptosis: programmed cell death After about 50 to 100 cell divisions, the cell dies, which is how the body protects itself against out of control cell division, which is cancer Initiation First stage in carcinogenesis marked by DNA damage which produces an initiated cell, which is neither normal or cancerous Damage may come from oxidative damage, free radicals, a carcinogen, or radiation
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Very few of these cell progress to cancer Promotion Second stage in carcinogenesis marked by more DNA damage which takes the cell from being an initiated cell to being a cancer cell Progression Final stage in carcinogenesis which produces a tumor Many cells are needed to make a tumor It takes 109 cells to be detectable A pea sized lump Angiogenesis Formation of new blood supply and without enough blood supply, tumors cant grow Malignant versus Benign Tumors Malignant tissue Invasive and metastasize(spread/grow) Metastasis The rapid spread of cancer cells to parts of the body distant from their origins Tumor detaches tumor cells into the bloodstream Prevention versus Treatment Treatment is limited to slowing or halting progression Phytonutrients and Cancer Phytonutrients are anti carcinogens which are capable of stopping genetic damage Phytonutrients exhibit a BLOCKING action Blocking Action Stop carcinogens from damaging DNA in the initiation and promotion stages Tomatoes contain compounds active against nitrates in the gut Detoxification Enzymes Body contains enzymes that eliminate dangerous chemicals These enzymes break the toxin down into simpler, less dangerous substances that can be excreted in the urine Certain fruit and vegetable compounds induce the body to produce higher levels of enzymes Sulforaphane found in broccoli and cabbage is partly responsible for the fact that people who eat more vegetables in this family get less cancer Phenols found in fruits and vegetables have the above affect Same with substances in grapefruit Phytonutrients are responsible for detoxifying many carcinogens and other toxin
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"Phase I" Enzymes create or activate procarcinogens into actual carcinogens have to opposite effect of the detoxification enzymes some plant compounds block this activation (isothiocyanates found in cabbage and broccoli) Antioxidants In high doses, antioxidant vitamins and carotenoids do not seem to prevent cancer Antioxidant rich diets DO lower cancer risk Promotion/ Progression Antihormones Estrogen and Cancer Estrogen promotes the growth of breast, uterine, ovarian, endometrial and other cancers of tissues that when healthy, respond to estrogen Early period and late menopause increase risk Pregnancy and breastfeeding temporarily lower estrogen levels which reduces the risk Estrogen Receptors Receptors are sites on a cell that bind to a hormone Lock(receptor) and key(hormone): only the right key will go into the lock Genistein from Soybeans Genistein is a compound known as an isoflavone from soybeans, and is like a very close to fitting key; a very weak estrogen; close enough structure to estrogen that it will bind to the estrogen receptor It blockades estrogen receptors Genistein is an antiestrogen, which is why we see less Asians getting breast cancer than Americans, because Asians eat more soy Too high intake of isoflavones may stimulate breast cell proliferation Tofu, tempeh, and soymilk are beneficial, supplements aren't Lignans Made from insoluble dietary fiber lignin by gut bacteria Lower blood levels of estrogen Ex. Flax seeds Indoles Found in broccoli and cabbage Induce higher levels of enzymes that lower amounts of an estrogen precursor With less precursor, less estrogen will be available Mevalonate Pathway Suppression
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The series of chemical reactions that synthesizes cholesterol Taking in these plant flavors and aromas may slow the growth of tumors Many plant aroma and flavor compounds decrease cancer incidence in animal studies Angiogenesis Genistein, the anti estrogen, blocks angiogenesis, the development of blood vessels Restricting this in tumors should slow their growth Phytonutrients and Other Disease Heart Disease Lowering the output of the mevalonate pathway lowers cholesterol These plant compounds will reduce cholesterol synthesis Phytosterols will also suppress cholesterol production Osteoporosis Genistein helps to keep bone minerals in place in post menopausal women Chemical Ecology Role of Phytochemicals in Plants Plants synthesize chemicals to kill bacteria and fungi Plants are not mobile so they produce bad tasting and toxic chemicals to repel the herbivores Plants depend on insects for pollination Plants have greater chemical diversity than animals Role of Phytochemicals in Food Phytonutrients are a key pat in good tasting food Recommendations Foods to Increase Phytonutrients in Your Diet 5 servings of fruits and vegetables per day Supplements Foods rich in phytonutrients keep you healthier Large supplemental doses can increase cancer Whole Foods Eat a diet rich in whole foods We know this works
Nutri Sci 132 Chapter 13
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Introduction An Ecological Perspective Pregnancy and breastfeeding are nutritionally demanding on the mother Preconception Nutritional Status and Fertility Conception: the joining of the sperm and the egg to form an embryo and the beginning of pregnancy Mother needs to go into pregnancy with good nutritional support The father needs good nutrition, as well Nutrients Required for Gene Expression Adequate Nutrition Important for Both Parents Once conception occurs, development is a function of maternal diet and other factors Embryo: the fertilized egg resulting from conception and developing into a fetus Congenital Anomalies A change form normal due to genetic damage or changes in gene expression Also called a birth defect May result in the inability of the fetus(an unborn human infant of more than 8 weeks) to survive and the mother may miscarry( spontaneous abortion of the fetus often caused by a congenital anomaly and occurring less than 20 weeks into the pregnancy) Teratogen An agent that damages genetic material or otherwise causes a congenital anomaly Nutrients Which Participate in Genetic Expression and Protein Synthesis DNA synthesis uses folic acid and zinc is a cofactor in the needed enzymes DNA protected from oxidative damage through selenium, vitamin C, vitamin E, and beta carotene Protein synthesis through amino acid metabolism(B6 and zinc) Preconception Nutritional Considerations for Women Anthropometric Factors Determined by body measurement High Body Fat Central obesity is associated with infertility BMI of greater than 30 means conception is less likely Low Body Fat Insufficient levels of estrogen to support menstruation (amenorrhea) A Body composition of less than 15% fat and normal weight women who have lost more than 1015% of their body weight have decreased levels of estrogen 1/3 of infertility is due to amenorrhea
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Biochemical Factors Anemia prior to pregnancy is a concern Iron needs double in pregnancy Poor iron status increases the risk of early delivery Poor folate can also cause anemia Low folate increases the risk of neural tube defects Clinical Factors Amenorrhea or oligomenorrhea Oligomenorrhea is having fewer than 6 menstrual cycles per year Negative energy balance, low dietary fat intake, and low body fat level can all reduce menstrual frequency High levels of activity reduce fertility Disordered Eating Anorexia amenorrhea infertility Binge eating disorder obesityinfertility Bulimia is less likely to disrupt fertility Polycystic Ovary Syndrome Sometimes seen in obese women High testosterone levels with abnormal body hair and acne Outer layers of ovaries becomes hard and thick preventing ovulation and resulting in infertility Diabetes Mellitus Needs to be under good blood sugar control prior to conception High blood sugar levels in the first 2 months of pregnancy are toxic and double and triple the risk of birth defects Pelvic Inflammatory Disease Related to STDs and IUD use, PID can cause scarring of the fallopian tubes, blocking the passage of eggs to the uterus Lead Exposure Women exposed to lead prior to conception store it in their bones Lead can reduce intelligence and executive function and increase learning disabilities in the fetus Anabolic Steroids Should be avoided Dietary Supplements Avoid high soy isofalvone, red clover, black cohosh and vitex
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Various weight loss supplements have an unknown affect on pregnancy and conception including CLA, hoodia, hydroxycirate, dexatrim and other amphetamine related drugs Avoid high doses of caffeine Dietary Factors Negative Energy Balance or Low Fat Intake Since very low fat intakes may bring about a negative energy balance, it can be hard to know whether the fat intake itself or the low body fat is at fault in amenorrhea Alcohol Modest amounts of alcohol reduce fertility Avoid alcohol while pregnant Caffeine Intake of greater than 300 mg/day (23 cups of coffee) prolong time required to become pregnant Lower intakes have not been shown to have negative effect on fertility Potentially Harmful Food Components Mercury: sometimes found in fish, can have an effect on the developing child's central nervous system Isoflavone Intake Found in soybeans, are weak estrogens and lengthen the time between menstrual periods, which may make it take longer for conception to occur Erythropoietic Nutrients 4 pints of blood are created during pregnancy in order to service the new infant and maternal tissues demands for erythropoietic micronutrients are HIGH high needs of iron and folate, B12, B6, and vitamin C Bone Nutrients Calcium and vitamin D are critical Preconception Nutritional Considerations for Men Anthropometric Factors High Body Fat Leads to lower fertility in men Low Body Fat Normal weight men who lose 1015% of body weight experience decreased sperm viability and motility Those who lose 25% of body weight, stop producing sperm entirely Clinical Factors
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Environmental Estrogen mimetics like PCB and DDT exposure lowers sperm count Isoflavones may have a similar effect Workplace exposure to glycol(antifreeze) may reduce fertility Exposure to heavy metal such as lead and mercury will reduce sperm count and fertility High environmental temperatures that raise the temp of the testes reduce sperm count Hot tubs and athletes training in heat may experience this Supplements Anabolic steroids shrink the testicles and eliminate sperm production Dietary Factors Nutrients Required for Sperm Production Zinc is a cofactor in enzymes involved in testosterone production, DNA synthesis, and cell division Hypogonadism: delayed or reduced development of sexual organs and secondary sex characteristics Caused by low intakes of zinc before adolescence and during early adolescence Sperm Protection from Oxidative Damage Sperm are very vulnerable to oxidative damage because they contain high levels of PUFA, whose double bonds are attacked by free radicals Antioxidants are needed for protection (Vitamin C, vitamin E, selenium, beta carotene) Low Energy Low energy intake decreases sperm viability and motility Alcohol Has a toxic effect on the testes and decreases testosterone levels Alcoholics have reduced fertility Moderate alcohol intake has little affect on fertility in males Pregnancy Fetal and Placental Development Fertilized egg forms an embryo After 8 weeks, the embryo is called a fetus After delivery, we have an infant Production of the infant takes 40 weeks Pregnancy is divided into trimesters First Trimester Second Trimester Third Trimester
Nutri Sci 132 Chapter 13
Weight: 1 oz Organs begin to form 15 weeks: heartbeat most vulnerable to teratogens Weight: 23 lbs Organs continue to grow Weight:78 lbs
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Spina bifida: a failure of the spinal column to form properly, leading to difficulties in gait or mental retardation Pregnancy considered successful if Gestation reaches 37 weeks Birth weight is >5.5lbs Placenta Organ that transfers nutrients and oxygen to the fetus, removes waste, and produces hormones Drugs are not filtered before entering the placenta which opens the fetus to harm Hyperplasia: growth occurs by an increase in the number of cells Hypertrophy: growth occurs by an increase in the size of cells Effects of Maternal Nutritional Deficiencies Undernutirion Infant Mortality Rate US ranks 26th Infants of low birthrate are more likely to die in the first year of life Birth Statistics Being underweight before pregnancy, poor weight gain in pregnancy, smoking, maternal infections, and early pregnancy iron deficiency all increase the risk of underweight/preterm birth Impact of Malnutrition Under nutrition before conception and in the first trimester can cause congenital anomalies and fetal death 2nd and 3rd trimesters, increased mortality, increased morbidity, and decreased learning capacity result from low birth weight prematurity Weight Gain in pregnancy Prepregnancy weight influences the amount of gain needed Anthropometric Concerns Components of Pregnancy Weight Gain 1/3 of pregnancy weight gain is actual fetus energy intakes exceed needs during the first trimester Prepregnancy BMI determines optimal weight gain Underweight woman may divert some of their nutrient intake to making up for their own deficiency Rate of Weight Gain
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Low rates of growth in the first trimester have the effect of down regulating fetal growth, causing lower birth weights Twin pregnancies recommend 3545lbs weight gain First trimester: 45lbs 2nd and 3rd trimesters: 0.751lb ber week Edema Abnormal accumulation of extracellular fluid Ankle swelling and tight fitting rings Biochemical Concerns Anemia Body has to synthesize a lot more blood due to the increase in weight gain Red cell mas increases 30%, plasma volume expands 50% Proper levels of hemoglobin during pregnancy are lower than non pregnancy Mild iron deprivation may deplete stores in hemoglobin concentration First trimester anemia increases chances of low birth weight and prematurity by 23fold Anemia later in pregnancy has smaller affects Lipid Metabolism Easier to acquire fat stores during the first half of pregnancy and live off them in the second half Blood lipid levels usually return to normal after pregnancy Carbohydrate Metabolism CHO is the preferred fetus fuel The mother develops greater insulin resistance to create higher blood sugar levels Preeclampsia A potentially serious condition of pregnancy Clinical Concerns Endocrine Changes 1st half of pregnancy is a time of anabolism in which the mother stores energy as fat, and produces tissues and systems to nourish the fetus 2nd half of pregnancy is catabolism in which the stores and structures are feeding the infant Preeclampsiaeclampsia Proteinuria: protein in the urine which is abnormal
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Eclampsia: a condition of later pregnancy involving high blood pressure that may lead to convulsions, kidney damage, still birth, and death To prevent, intake adequate amounts of vitamin C and E, folic acid, and omega3 fatty acids Gestational Diabetes Diabetes that arises during pregnancy Stems from the resistance to insulin used to shunt glucose to the fetus of women who develop gestational diabetes during pregnancy either get Type 2 later in life or develop it again during other pregnancies genetically predisposed to this Gastrointestinal Problems Nausea and vomiting Extremely common during pregnancy First trimester more common 4th to 10th weeks of pregnancy avoid smelly foods better tolerated are carbs, fruits, salty foods, and dairy ginger and ginger ale Constipation Placental hormones lower muscle tone Reduced strength of the peristaltic contractions that move food through the gut so constipation results Treatment: fiber rich foods, fluids, and exercise Esophageal Reflux(Heartburn) Caused by placental hormones Stomach acid irritates the esophageal lining Treatment: eat small meals, slowly Supplements Herbal and non nutritional supplements are dangerous in pregnancy Dietary Energy Energy needs increase 1st trimester, very little extra is needed 2nd trimester, extra 350kcal per day 3rd trimester, extra 450kcal per day
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Nutrient Density Important Increased energy should be supplied by nutrient dense food Meal Skipping Avoid this during pregnancy because the fetus gets most of its energy from carbohydrates Higher Energy Needs in Some Individuals Pregnant adolescents need more energy than pregnant mothers Women underweight before pregnancy have higher caloric needs Active people have to eat more food to keep up with their expenditure Failure in all of these cases to eat more may result in low infant birth weight PreDelivery Fasting Some institutions say to fast before birth, but it is advised to eat before delivery Exercise Women active before pregnancy should remain active, though intensity and duration may need to decrease Women who were never active are encouraged to become active which makes for an easier delivery Moderate intensity Strength training should be lower resistance, higher repetition Avoid activities with a risk of falling, compress the abdomen, overheating, dehydration, exhaustion, contact sports, scuba diving, and bouncing Protein 0.8 g protein/kg of body weight plus 25 grams each day Carbohydrate Ketone bodies: products of fat metabolism harmful to the fetus in high concentrations These build up in the mothers blood and cross through the placenta into the fetus if inadequate carb intake High levels of ketone impair growth and intellectual development in the fetus Lipids Omega3 PUFA are important in fetal development Better neurological development and improved pregnancy outcomes in women consuming adequate amounts Micronutrients Gene Expression and New Cell Synthesis Folate: necessary in DNA synthesis Vitamin B12: activates folate so it is needed, too
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Zinc and Vitamin A: retinol form is teratogenic; any supplement should be in the beta carotene form; Acutane and RetinA can cause birth defects and brain malformation Erythropoiesis Increased blood volume and placental and fetal growth Inadequate iron intake may result in stillbirths, premature births, and low birth weight infants, along with lower IQ Iron supplements may be required Vitamin B6: needs are increased because increased protein consumption and increased activity of enzymes that require pyridoxine as a cofactor Folate needs are higher to support greater cell division Bone Nutrients Increased gastrointestinal bioavailability helps meet needs for increased maternal bone synthesis Low calcium intake leads to release of heavy metals from bone; another risk is high blood pressure in mother and infant Low vitamin D: infants tend to be smaller and have poorly formed bones and poor tooth enamel Alcohol FAS: affects IQ, executive functions(judgment, impulse control, and understanding what appropriate behavior is); can cause facial malformations leading cause of mental retardation in the US and world avoid alcohol during pregnancy Caffeine Crosses the placenta and affects the fetus Low birth weight, miscarriage, still birth, premature birth, and congenital anomalies are risks Less than 300mg/day is considered safe Heavy Metals Lead and mercury are cumulative and dangerous Pica Eating of non food materials and is more common during pregnancy Carries risk for toxicity Common items: laundry starch, wall plaster, mothballs, and dirt Raw Meat, Fish, Seafood, and Milk AVOID during pregnancy Too high risk of parasites and food borne illness
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Aspartame and Saccharin Avoid during pregnancy Vegetarian Diets Make sure to consume plenty of plant proteins Vitamin D deficiency, known as rickets, cause bone malformation Probably need to take iron supplements Probably need B12 supplement too because deficiency can cause neurological deficits Lactation Breastfeeding Trends Benefits Mother and infant Ever since infant formula became available, it began to replace breast milk Breastfeeding is a trend, though today most are breastfed Infant Benefits Designed for Infants Mineral Bioavailability Very high bioavailability Far better source of iron than cow milk Medium chain Triglycerides Breast milk is rich in MCTs when the mothers fat intake is low and calories come mostly from CHO and fat An easily absorbed form of fat Omega3 Fatty Acids Breast milk is a great source Great source of DHA Necessary for development of CNS and vision Formula lacks DHA ALA also present in breast milk Casein to whey Ratio The 2 kinds of protein Cows milk: 3040% whey, 6070% casein Hard to digest for human infants Breast Milk: 6070% whey, 3040% casein Highly digestible for human infants Bacteriologically Safe Mothers milk contains no harmful pathogens(disease causing bacteria) Doesn't introduce disease to the infant
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Formula may mix with contaminated water Mothers milk has protection against the infant getting an infection White blood cells(which fight disease) are in breast milk Immunoglobulins, proteins that fight infection, are in breast milk Bind iron and B12 making them unavailable to bacteria in the infant gut Breastfed infants get less diarrhea, which leads to dehydration, which leads to death Allergies and Infections 30% increase in allergies for infants who are fed formula 25% increase in asthma for infants who are fed formula breastfed infants in the US get 20% less ear infections, 80% less prolonged infections, suffer 17% less coughing, and 29% less vomiting breastfeeding reduces the risk of Sudden Infant Death Syndrome breast milk has an analgesic effect, reducing the experience in pain in infants Gastrointestinal Disorders Breast feeding reduces the risk of celiac disease and inflammatory bowel disease, as well as the risk of childhood cancer Obesity Prevention Breastfeeding may lower the risk of childhood obesity Cognitive Development Breastfeeding may enhance cognitive development Higher IQs have been linked to those breast fed for 1218 months Maternal bonding Breastfeeding creates a stronger bond between mother and infant Close contact Maternal Benefits Physiological Breastfeeding induces anovulation, the state of not ovulating that is not releasing eggs Release of the hormone oxytocin due to lactation causes the uterus to contract, restoring it to its former pre pregnancy size Breastfeeding mobilizes fat stores to provide lipid for milk production and an energy source for the mother Requires an extra 750 calories per day in the mothers diet to make milk Weight gained in pregnancy is often not lost Breastfeeding can be an easy way to lose weight without restricting calorie intake Exercise and breastfeeding combined can lead to pre pregnancy weight Breastfeeding also lowers a woman's risk for reproductive tissue cancers
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Physical Convenient to breastfeed Correct temperature Clean Ready to go Free of charge Psychological and Emotional Infant and mother bond becomes closer Colostrum Milk released from mammary gland up to 35 days after birth Differs from regular human milk Increased levels of immunoglobulin Facilitates establishment of Lactobacillus bifidus in the infant's GI tract LB is a benign bacteria used to exclude potential pathogens from growing in the GI tract Contains increased amounts of protein, electrolytes, iodine, beta carotene, copper, and zinc Decreased lipid, carbohydrate, and caloric density Mature Human Milk Fatty acid present depends on what fatty acids the mother consumes "fore milk" released at the beginning of nursing increased nutrient density and decreased caloric density "hind milk" released at the end of nursing increased lipid content and caloric density higher fat milk for satiety at the end the more milk an infant removes from the breast, the more milk the mother synthesizes Initiation and Maintenance of Lactation Estrogen, progesterone, placental lactogen, and chorionic gonadotrophin levels drop after peaking at birth While pregnant, these hormones stimulate massive proliferation of cells of the mammary glands to prepare for lactation Prolactin: stimulates milk production Oxytocin: stimulates letdown(the reflex that releases milk from the milk gland into the milk duct) Anthropometric Factors Body Composition after 6 weeks postpartum 6 weeks: blood volume and uterus size have returned to normal
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at this point, any extra body weight is fat Losing Pregnancy Body Fat Should lose all fat by 6 months postpartum Weight Loss and Milk Production Loss of 1lb per week will not impair milk production or infant growth Biochemical Factors If anemia is still present, continue on iron pills Clinical Factors Hospital Practices that Influence Breastfeeding Initiation Practice frequent nursing Burse early, nurse often Medical Contraindications Very few reasons against breastfeeding Reasons are HIV positive Mothers on some medications Mothers taking street drugs Conditions Related to Breastfeeding Sore nipples Try removing caffeine from diet Overactive let down reflex Causes infant to choke on milk Engorgement, when the breast is overfilled with milk, seen in the first 2 weeks of first time mothers Nurse infant frequently, every 12 hours Plugged ducts result from incomplete emptying of breasts Change nursing positions Mastitis, a breast infection, occurs through a blood borne source of infection Medications Don't breastfeed if on Lithium Ergotamine Chemotherapy Radioactive isotopes Drugs that suppress milk production Street drugs
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Allergy Prevention Best protection against potential allergies is breast feeding Mother should avoid foods that have a history of allergies in the family while breastfeeding Nicotine Decreases milk production Wait 2 hours after smoking to nurse Don't smoke in the presence of the infant Environmental pollutants Not found in high enough amounts in breast milk to offset health benefits of the milk Exercise Benefit the mother by helping her lose pregnancy weight Nurse before exercise Dietary Factors Malnutrition An underfed woman will synthesize nutritionally adequate milk, but not enough Volume is the issue Fluids Milk will be made at the expense of maternal fluid status Sweat losses means more fluid will be needed Energy Milk energy obtained from maternal lipid stores and the diet Nutrient Density Increase in energy should be supplied by nutritionally dense foods Avoid Fasting and Meal Skipping Forces an increase reliance on fat metabolism Ketone bodies in milk can cause harm to the infants Protein Lactating women need 1.1g protein/kg of body weight Carbohydrate Need carbohydrates Lipid ALA: 1.3 g/d in order to get enough milk The infant needs essential fatty acids including ALA for nervous system development Mother should maintain a 6:1 ratio of omega 6: omega 3 Micronutrients(Vitamins and Minerals)
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DRI are the same or greater during lactation compared to pregnancy Exceptions are thiamin, niacin, folate, magnesium, and iron Vitamin D can be supplied by sun exposure Iron may need to be supplemented if mother's measures are low Alcohol None during pregnancy No heavy drinking during breastfeeding 22.5 ounces per day (8oz of wine per week or 2 beers) better not to drink don't use alcohol to calm a fussy infant caffeine caffeine passes into the breast milk but not to a great extent babies cant metabolize caffeine until 34 months old some babies are sensitive to caffeine which makes them hyperactive and fussy wait 2 hours after caffeine to breastfeed Barriers to Breastfeeding Returning to work schedule to nurse at lunch, use pumped milk, or supplemental formula, breastfeed a lot when you get home Express milk at work refrigerate for later Wear clothes that make it easy to feed Lactation Promotion and Support Certified Lactation Educator Credential Most problems in lactation are due to a lack of coaching WIC Supplies formula for bottle fed infants and food and support for mothers who have low incomes Infants Anthropometric Factors Weight Infants are meant to grow rapidly Peak growth period in life No distinction between growth between genders until 10 years old Infants are typically weighed monthly Body Length Mean birth length: 50cm increases by 50% in the first year Short reflects long term malnutrition
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Head Circumferences Useful measure of nutritional status up to 3 years Growth Charts Consistent velocity for growth is good Malnutrition usually produces a less consistent growth pattern Concerns Infants normally lose 7% of body weight at birth >10% loss is a cause for concern Failure to Thrive: infant has a pronounced lack of growth Below average in weight and height Biochemical Factors Anemia A concern if there was maternal anemia during pregnancy 2 minute delay in cutting the umbilical cord can boost iron reserves in infant for months Blood Fluoride Enough is important in strong teeth Clinical Factors Normal Development Gradual increase in motor skills, coordination, and talking Happen at a predictable rate Gastrointestinal Function 1st week post birth: 34 soft yellowish stools and 6 wet diapers/day soft stool is okay in a breastfed infant 6 months until the GI tract matures avoid cow milk for the first year constipation: due to soy based formulas Colic is a sudden onset of crying and fussiness Unknown cause Feed and burp in proper position to relieve GI gas Dietary Factors Basis of Nutritional Requirements Infant growth rate is a strong predictor of nutritional status Infant needs are much higher per kg of body weight because of rapid growth rates Energy Needs 06 months: 108kcal/kg
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69 months: 98kcal/kg Expenditure Infants have a high BMR Double that of adults Temperature Regulation Constant core temperature is very important Hard to maintain in infants Growth Needs include the energy cost for synthesis and conversion of tissue Needs decrease with age 3 months: 30% of energy needs 6 months: 1015% of energy needs Protein 06 months: 2.2 g/kg 612 months: 1.6 g/kg high biological quality protein is best Carbohydrate No dietary fiber requirement for infants Lipid Primary source of energy for infants Content Human milk provides 55% of kilocalories as lipid Cholesterol content of human milk is high Formula cholesterol is low Composition Depending on intake, it plays a role in brain development Vitamins and Minerals Vitamin D Recent increase in rickets has been observed Allow child to some sun exposure, prior to putting on sunscreen Iron Enhanced erythrocyte synthesis occurs at 46 months of age Delay umbilical cord clamping to improve iron stores Fluoride Permanent teeth begin developing by 34 months Needs to be given directly to the child if needed
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Early Infancy Nutrient needs can be met by exclusive use of human milk or formula Late Infancy(612 Months) Solid foods Not given until infants are 46 months Could be problems Food allergies GI tract isn't developed Choking First foods are usually rice cereal mixed with milk Children get used to the flavor of their culture 46 months: food should be completely pureed 68 months: food should be lumpy but soft 810 months: soft and mashed cup introduction and weaning 56 months: begin drinking from a cup 1224 months: consume all liquids from a cup no juice in cup until 1 year Food to avoid during Infancy High risk for choking should be avoided Honey should be avoided in the first year due to a potential of infant botulism Don't put hot liquids in plastic cups Recommendations Balanced healthy diet Avoid alcohol Adequate energy intake is essential Infants should be breastfed for about 1 year No solid food until 4-6 months of age
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Nutri Sci 132 Chapter 14
Introduction Better growth and development as a result of good feeding An Ecological Perspective Human children are mimics, they learn by watching Healthy family environment is where children learn how to eat Childs health is determined largely by their family Child nutrition is all about parenting Feeding Children Nutritional Needs of Childhood Toddlers: child in the second year of life and beyond
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Slower Growth Rates Growth slows down Nutritional needs are lower Nutrient dense foods are important Transitioning Fat and Cholesterol Intake Getting enough calories becomes less of a challenge Growth of nervous system slows Reducing demands of cholesterol After age 2 or 3, the toddler should follow adult dietary guidelines for fat and cholesterol Serving Sizes Up to age 3, a serving is 1 tablespoon per year of life Fluid Needs Depend on activity level Toddlers: about 5 cups of fluid per day Older children: 9 cups of fluid per day Teaching an Appreciation for Good Food Learning to Make Choices Need to make good choices Let children make small decision and fail, so next time they will use better judgment Use trial and error Help kids to learn to eat wisely Nutrient Dense Foods We want kids to prefer the nutrient dense foods
Nutri Sci 132 Chapter 14
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We want their diet to be moderate in fat content and low in sugar content You are the Model for How you Eat Kids pick up on parental attitudes to food while eating Eating disorders and obesity have a family component Exposure Kids eat the foods to which they are exposed Good Food Eating should be a quality fun experience for kids And Repeated Exposure Expose kids to new foods until they are willing to try it Research shows kids need to see a new food between 12 and 20 times until they try it The Right Attitude Let eating the food be a choice Only Positive Emotional Associations with Food Negative Emotions Around Food Cause Problems Contribute to eating disorders You fight over food, you lose Nothing you can do to make a child eat Never Beg, Bribe, or Reward Offer food Bribing and rewarding with food send the wrong message Watch for the Underlying Message Watch what you say about food because it may send the wrong message Food is not Love We don't want to use food as a replacement for love or affection Don't put kids in front of the TV with a snack to keep them occupied Involving Kids in Food Help to develop positive approach to eating Let the kids cook Let kids garden Childhood Food Preferences Children like a crisp texture Instead of chips, try apples or carrots or graham crackers
Nutri Sci 132 Chapter 14
Manageable size Cut the food to bite size Mild flavors Like a blander food palate Comfortable temperature Cool off hot foods, warm cold ones NOODLES Environmental Concerns of Childhood Lead: can affect the CNS, drop in intelligence, learning disabilities, short attention spans, affecting school performance Most common source today is lead paint and windows
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Nutri Sci 132 Chapter 15
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Introduction 2 important aspects of food safety microbiological safety presence of disease causing bacteria or other organisms in food chemical safety presence of harmful chemical substances in food, toxins or teratogens An Ecological Perspective Even though the US food supply is the safest and foodborne illness is at an all time low, there are more ways to get sick than ever before Microbial Safety Food poisoning: results from microbial contamination Bacteria either Causes an infection in the host Or produces toxic metabolites Food poisoning different than food spoilage The pathogens that cause poisoning are different in spoiled food Common Foodborne Illness Foodborne Infections Bacteria infects the host Host has to ingest the bacteria Symptoms begin hours or days after Campylobacter Causes more diarrhea than any other in the world Fever, vomiting, cramping Found in birds and raw poultry Common cause: undercooked chicken Norwalklike virus or Calicivirus Cause of vomiting Less diarrhea Lasts a couple of days Passes from person to person No animal host Salmonella Causes diarrhea, fever, cramps
Nutri Sci 132 Chapter 15
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Gut of mammals, reptiles, and birds E. Coli O157:H7 Bloody diarrhea and severe cramping Little fever From traces of cow or animal manure Listeria Uncommon infection mostly in infants and elderly Attacks people with poor immune systems Muscle aches and can spread to the nervous system Pregnant women can pass it to the newborn Other illness Giardia Shigella Hepatitis A Cryptosporidia Foodborne Toxins Botulism Induces paralysis Often fatal Staphylococcus Skin bacterium Causes vomiting Dangers Foodborne illness could cause you to end up with damaged kidneys, paralyzed, or dead Sources Foods that pool parts of different animals increase pathogen likeliness to spread Fruits and vegetables should be washed 2006: E Coli outbreak in spinach sprouts are a particular concern prime candidate for foodborne illness unpasteurized fruit juices Prevention Regulatory
Nutri Sci 132 Chapter 15
FDA USDA Personal Precautions Clean Wash hands and food products Separate Avoid cross contamination Cook Make sure food is cooked enough Chill Keep hot food hot and cold food cold Report Report foodborne illness to the local health department Chemical Safety Additives Food colors Preservatives Extend shelf life and prevent rancidity Thicken foods Modified food starch or soluble fiber Moisten Dough conditioners Fortification Adds micronutrients not already present Retinol (Vitamin A) is a huge concern for too high of an intake Additives aren't naturally present in food You can usually get by without them They aren't that dangerous Additives are a mark of highly processed food Contaminants End up in food by accident Melamine In Chinese milk and infant formulas
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Nutri Sci 132 Chapter 15
Nitrogen containing industrial chemical Poisoned thousands of children BPA Scare in plastic bottles Never directly added to food but leaks in from cans and bottles BPA has an estrogenic effect Effects people in a subtler and less sever way Pesticide Residues Applied to vegetables and fruit Never good for you ALL are toxic Hard to quantify the effects of pesticides Organic Produce Delivers produce with little to no pesticide residue Organic is better for the environment too Animal Products Seldom contain pesticide residues May contain PCBs and dioxins Experimental Evidence Lack of experimental evidence Value of Organic Produce May turn out to be healthier, but has yet to be proven More environmentally benign Antibiotic Usage Given to some healthy animals to prevent disease Sometimes given to promote growth Problem: making bacteria resistant The more exposure to a drug, the more resistant of a population there is Organic growers only use antibiotics to treat sick animals Recommendations Support Strong, Empowered, and WellFunded Food Safety Institutions FDA: oversee the food supply USDA: maintain organic certification
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Nutri Sci 132 Chapter 15
Organic Food US has the safest food supply Organic is better for the environment and uses less energy Keeping It in Perspective Pesticides do not Present the Risk that Smoking or Saturated Fat do to Health Don't smoke, exercise, reduce saturated fat, eat fruits and vegetables Any Vegetables are Better than No Vegetables Get organic if possible, but non organic are still good for you Its not Worth your Last Dollar If you can afford, buy organic, but don't stress Inorganic is still good You Cant Eliminate Risk Altogether There will ALWAYS be some risk
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Nutri Sci 132 Chapter 16
Introduction Lifestyle is not the same as quality of life Health and happiness aren't just internal states An Ecological Perspective: It's All About Energy Obesity epidemic is the biggest public problem we face Smoking consumes more health care dollars Obesity is all about energy balance Climate change caused by global warming is our biggest environmental challenge Lifestyle Determines Resource Use Your CO2 production is sometimes referred to as your carbon footprint Amount of CO2 produced by an activity or a person Measure of contribution to global warming Our choices have a direct effect on our consumption Steps in Reducing your Environmental and Climate Impact Steps Which Decrease Human Energy Intake and Environmental Impact Eat lower energy density food Foods should look like what they did when they came from the farms Processing also tends to add packaging Prepared foods also tends to add packaging The trend is towards more and more meals being eaten away from the home Many of those fast food meals are heavily packaged Steps Which Decrease CO2 Production in Agriculture and Food Distribution Trying to find environmentally sound ways to produce food Buy locally produced food Eat Locally Produced Food Today, the modern food supply is highly globalized Food today tends to travel a great distance before you eat it Better Quality Some of the best fruits and vegetables just don't ship well The closer the fruit comes from, the fresher it is Eating locally means eating what's in season Energy Savings Energy saved in transporting food if it comes from close
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Nutri Sci 132 Chapter 16
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Social and Economic Benefits Eating locally supports your local economy and agriculture Today, rural communities need all the help they can get When you buy local production, money stays in the community creating jobs and strengthening local institutions Local, but Not Inflexible Doesn't need to be an all or nothing thing buying only locally grown food Bananas are the number 1 fruit eaten in the US In some cases like producing cheese, it may cost more to produce that to ship since you need a certain climate Access to Locally Grown Food Biggest problem is finding local grown food Best bets are farmers markets Food co ops are another good place to get fresh local food Community Supported Agriculture, CSA, is when you buy a share in a farmers production at the beginning of the season Weekly, you get deliveries The Ultimate Local Food Your Garden Most vegetables in this country come from home gardens Home gardening is very convenient You only go to the store for staples and you shop and spend much less Importance of LocallyGrown Food Reduces carbon emissions How far food is shipped is more important than how it is grown Local is more important than organic Sustainable Agriculture Sustainability Defined Sustainable agriculture looks to minimize carbon output It is intended to last Minimizes dependence on resources that will one day run out Low Input Sustainable Agriculture Versus Organic Farming Organic farming: agriculture that completely avoids the use of chemical pesticides and chemical fertilizers Low input sustainable agriculture minimizes chemical fertilizer and pesticide while organic agriculture eliminates them Renewable Resources
Nutri Sci 132 Chapter 16
Resources that are constantly being replenished Energy from wind, sun, and biomass
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Nutri Sci 132 Chapter 16
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Soil Fertility Growing plants require sun, N, P, and K They also need iron and calcium Need fertile soil to support plant growth Potassium and phosphorus have to come form the ground Nitrogen comes from the air Legumes grow in nitrogen poor soil Soil Conservation Soils have a fertile topsoil layer Eroded subsoil don't have the ability to grow food Crop Pests and Diseases Pests cause a loss of yield and even destruction of crops There are now other ways than just pesticides to keep pests away Farm Chemicals can Affect Human and Environmental Health PCB and DDT are fat soluble That means they are stored in the body and there is no good way to get rid of them Crop Protection Crop rotation, grow different crops in different soils each year Cultivation, the removal of weeds Integrated Pest Management uses pest control chemicals in minimal amounts Genetically Modified Organisms(GMOs) Plant breeders no longer have to wait for useful mutations to arise GMOs have caused controversy: many countries don't want these to be used because of health concerns; allergen risk Advances in plant breeding may be reducing the need for GMOs Resource Efficient Animal Production 10:1 ratio of energy value of the feedstock to the energy value of the finished meat Poultry is 3:1 Fish farming can be 1.2:1 Eat animal products to get enough B12 Also to get enough iron, calcium, and zinc Free range: little grain fed Buy free range meat when available Accessing Sustainability Produced Food
Nutri Sci 132 Chapter 16
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Like local foods, these are harder to find in the supermarket Being organic makes a food sustainable You can ask the producer directly how their product is grown which is a benefit of buying close Changing the Food Production System US has the most efficient system of agriculture in the world We save labor with energy which is very efficient in terms of dollars Cover crops for soil protection and green manure require work in the fields Environmentally sound practices strive to be resource efficient and energy efficient They may not be as dollar efficient in the short term Farmers need our support: Public policy such as tax credits, price supports, incentives, and various farm programs Farmers need our economic vote by buying products that you believe in ... Or not the alternative is to do nothing climate change is likely to worsen the nutritional status of the most poorly nourished people on the planet prevention is vastly easier than cure Steps Which Increase Human Energy Expenditure and Reduce CO2 production Do Work Manually Where Practical Years ago, exercise wasn't an option because if you wanted to eat, you had to work the fields Most people today don't do physically taxing jobs Use Self Powered Transportation Commute to work and such by walking In other cities, there are less joggers on the street than in the US but more walkers and bikers Bike commuting can save time Engage in Low Carbon Recreational Activity Consider the environmental impact in choosing what recreational activities to do Recommendations Shop at farmers markets and food coops Join a CSA farm Garden Buy locally produced food Bike and walk when you can
Nutri Sci 132 Chapter 17
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Introduction The Gulf Between Belief and Action Knowing what's good for you by no means guarantees that you'll do it Free will: we get to choose our actions for better or for worse and this is what makes us human An Ecological Perspective Healthy food choices were simple in the past 50,000 new products are produced each year with this greater variety, has come a greater freedom of choice your health is not the food industry's first priority Understanding Behavior: Concepts Driving Forces Behind Eating Behavior and Food Choice Hunger(Physiological Need) The body needs fuel, nutrients Hunger is the purest driving force for our eating Satiety is the condition of having met our physical needs It's the sense of being full and satisfied Innate Food Preference Preference governs our choice of one food over another Some preferences are innate while some are learned Sweets Strongest innate preference Never lose an enjoyment of sweets Years ago, sweet foods were berries and carrots Today, they are additives in certain foods Fat and Satiety Have some inborn preference to fat Fat isn't as scarce as carbohydrate Satiety is what tells us to stop eating Fat is often said to promote satiety Variety Innate desire for a varied of diet Variety increases the odds that nutrients will be obtained in foods Flavors
Nutri Sci 132 Chapter 17
Some people have a genetically despise of bitter foods such as Brussels Sprouts Learned Food Preference Most of our food preferences are learned Sugar The degree to which we like things is learned Eat fewer sweets and you will learn to not need as many and to appreciate milder sweets Fat Low fat foods are no less inherently likeable than high fat foods preferences for fat can be relearned Flavors One can learn to prefer flavors Ex. Certain people like more salt The southern states eat half as much salt as the northern states Sensory Qualities We learn to prefer certain textures, temperatures Sometimes a healthier food of a similar texture can substitute Availability We eat what's available and convenient Normal weight people eat less of highly available food Social When people are happy they eat together Eating is a way of connecting with people Emotional Need(Comfort) Eating is a comforting activity Eating comfort foods on occasion is fine It is important to get pleasure from eating but not if what your eating is only bad Rational ChoiceNutrition Knowledge Many people change their habits when they learn about nutrition Humans don't always do what they know is best for them Habit Sometimes we do what we do because we've always done it Order Varies with Individual and Circumstance Depending on the circumstance drives you to eat certain things
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Nutri Sci 132 Chapter 17
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Unmet needs with influence eating the most Most of this is Subject to Your Influence You get to make your own destiny to a very large extent when it comes to eating You can relearn preferences, establish new patterns, and break programmed responses Making Your Value in Line with your Biology Preferences and Values choose values that work for you learn to prefer things that work well for your body learn to like things that make your life better Barriers to Behavior Change Other Priorities Your health cannot always be your top priority in your life Nutrition should actually not be your first priority in life While eating well cant be a high priority at all times, but don't put it off all the times Distraction People stop exercising because of lack of time when the average American spends so much time each day watching TV If you cant get around to changing your lifestyle, think about what you could give up that would free up your resources, time, and energy Shame If we are too ashamed to address a behavior, we don't seek help Denial Related to shame If we deny we have a problem, we don't address it We need to admit the truth Overwhelm Occurs when we take on the reality of our problems too much Don't take on too much at once Make commitments to yourself but don't be afraid to change them Pragmatic Problems Most of the time if you don't want to be flexible in finding a gym close to you and you refuse to walk outside, there are deeper issues Understanding Resistance There has to be something stopping you from making that change Identifying Barriers to Change Initial step is to understand the nature of the obstacle
Nutri Sci 132 Chapter 17
Step outside the situation Self diagnosis can be dangerous Changing Behavior: How To Making Your Health a Priority Health and nutrition may be important in supporting your other priorities Prioritize change narrow your focus and work on your highest priorities identify your top 3 problems and focus on them Make Change Sustainable and Realistic Balance, Moderation, and Variety Restriction usually backfires and causes you to crave Food Specific Behavior Learn to moderate behavior Stay away from the food in the first place Uncoupling Eating and Emotion Meet your emotional needs appropriately Substituting behaviors Learn hunger cues Don't Shame Yourself Find a way to meet your needs with fewer negative side effects Coaching Registered Dieticians Counseling How to access this help Physician referrals Some universities Self Assessment Tools Consciously eat and live Behavior Modification Tips Convenience and satisfaction Set yourself up for success Cook Make it easy Make it fun Learn how to cook quick Portable foods can help in an on the go life
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