Ch 1 - 8/25/09 GeneralPrinciplesofNutri2on Chapter1...

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Unformatted text preview: 8/25/09 GeneralPrinciplesofNutri2on Chapter1 Whatisnutri2on? Nutri2onis "thescienceoffood,thenutrientsandthe substancestherein,theirac2on, interac2on,andbalanceinrela2onto healthanddisease,andtheprocessby whichtheorganismingests,absorbs, transport,u2lizes,andexcretesfood substances"TheCouncilonFoodandNutri2onofthe AmericanMedicalAssocia2on 1 8/25/09 Nutri2on Specificnutri2onalneeds Athletes Physicallyac2ve Nutri2on Growthanddevelopment Providesenergy Regulatesmetabolism Macronutrients Micronutrients Nutri2on Macronutrients Carbohydrates(CHO) Fats Protein(Pro) Carbohydrates Photosynthesis FormsCHO Plants 2 8/25/09 Carbohydrates MonosaccharidesCH2O GlucoseC6H12O6 FructoseC6H12O6 GalactoseC6H12O6 Arrangementofatomsunique Carbohydrates Monosaccharides Glucose Galactose Fructose Disaccharides Sucrose Glucose,fructose Lactose Maltose Carbohydrates Oligosaccharides 3to9monosaccharides Vegetables Carbohydrates Starches StoredCHOinplants Amylopec2n Amylose Polysaccharides 10ormoremonosaccharides 3 8/25/09 DietaryFiber Retainsconsiderablewater Gives"bulk"tothefoodresidues Bindsordilutesharmfulchemicals Shortenstransit2meforfoodresidues Glycogen Aglycogenmoleculecontains hundredsofglucoseunitsinhighly branchedchains.Eachnew glycogenmoleculeneedsaspecial proteinfortheaFachmentofthe firstglucose(shownhereinred). Starch(amylopec:n) Starch(amylose) (andpossiblycarcinogenicmaterials) Astarchmoleculecontainshundredsofglucose moleculesineitheroccasionallybranched chains(amylopec:n)orunbranchedchains (amylose). Helpslowercholesterol SteppedArt Fig.48,p.106 DietaryFiber LowfibervsHighfiber 4 8/25/09 DietaryFiber Nurses'study Addi2onal5gfiber Reducedhearta^ackriskby37%. Func2onofCHO Exerciseperformance Centralnervoussystem(CNS) Prolongedstarva2on Hypoglycemic Ketones DiabetesType2 Fiberplusmacronutrientsdecreasesrisk Increasebody'ssensi2vitytoinsulin CarbohydrateIntake Westernworld 4050% CarbohydrateIntake Westernworld 50%ofCHOconsump2on Simplesugars Athletes Atleast60%dietaryintake 5 8/25/09 HighBloodGlucose Mayoccurfromconsumingmanyfoodswithahigh glycemicload Mayoccurduetoinsulinresistance,insulindeficiency, orboth,andresultintype2diabetes MetabolicSyndrome(SyndromeX) Insulinresistancesyndrome 25%ofyoungadults,>50%age55+ Poorbloodglucoseregula2on Type2diabetes Heartdisease Hightriglycerides Hypertension MetabolicSyndrome Riskfactors Obesity Lackofphysicalac2vi2es Highsimple/refinedsugarintake Lowfiberintake 6 8/25/09 CarbohydrateIntake Westerndiet Sportsdrinks Sojdrinks Sugarcontent(1020g/100ml) CarbohydrateIntake Fiberrecommenda2on 1013g/1000kcal 2035g/day Westerndiet 14to15g/day FiberIntake www.mypyramid.gov DietaryLipids 7 8/25/09 History 1918Aron Firstproposedthatfatmaybeessen2alfornormal growthofanimals 1927EvansandBurr TestedonanimalsVitaminsA,D,Eadded Fatdeficiencyseverelyaffected Bonegrowth,Reproduc2on CalledVitaminF Essen2alsubstancecontainedinfat History 1929Burr Nutri2onalimportanceofspecificlipidsinfat Fatfreedietrats Impairedgrowth Scalyskin Tailnecrosis Increasedmortality Lipids Lipidisageneraltermforaheterogeneous groupofcompounds. Oils,fats,waxes,andrelatedcompounds Simplelipids Compoundlipids Derivedlipids Symptomsreversedwithlinoleicacid Coinedtermessen$alfa)yacids(EFA) 8 8/25/09 Lipids Simplelipids Neutralfatsconsistprimarilyoftriacylglycerols Triglycerides Triglycerides Triglycerides C,H,O Composedof3fa^yacids(FA) Glycerolmolecule TGvaryinthetypeofFAandtheirbonding pa^ern FAvaryinthenumberandarrangementofdouble bonds UsuallyevennumberC Majorstorageformoffatinadiposecells Ace2cAcid Triglycerides 9 8/25/09 Fa^yAcids Saturatedfa^yacids Singlecovalentbondsbetweencarbonatoms Covalentbondsshareelectrons Triglyceride Alloftheremainingbondsa^achtohydrogen. Fa^yAcids Carbonchainlength Long(C12C24) Meat,fish,vegetableoils Fa^yAcids Medium(C8C10)andshort(<6C) Dairy 10 8/25/09 Fa^yAcids Unsaturatedfa^yacids Oneormoredoublebondsalongthemaincarbon chain. Monounsaturatedfa^yacidonedoublebond. MUFA Fa^yAcids Stearic acid, an 18-carbon saturated fatty acid Polyunsaturatedfa^yacidtwoormoredouble bonds. PUFA Fa^yAcids Oleic acid, an 18-carbon monounsaturated fatty acid Essen2alFa^yAcids Doublebonds Omeganumber C20:43 Posi2onoffirstdoublebond Omega3FA3rdposi2on Linolenicacid Omega6FA6thposi2on Linoleicacid 11 8/25/09 LinolenicAcidomega3 Fa^yAcidsomega6 Linoleic acid, an 18-carbon polyunsaturated fatty acid Essen2alFa^yAcids Omega-3 Omega 6 Essen2alFa^yAcids DHA,EPA Decreasebloodclorng Notwithan2coagulantmedica2onorsurgery Reducehearta^acks Alpha-linolenic acid Linolenic acid Fishoilshaveanan2arrhythmiceffectonmyocardial2ssue. Immunefunc2on Decreaseinflamma2on,pain DHA (docosahexanoic acid) EPA (eicosapentaenoic acid) Arachidonic Acid 12 8/25/09 Essen2alFa^yAcids DHA,EPA(cont) Toomuchhemorrhagicstroke Otherpossibleuses:Lowertriglycerides, rheumatoidarthri2s,Alzheimer'sdisease CompoundLipids Consistofatriacylglycerolmoleculecombined withothersubstances Phospholipids Glycolipids Lipoproteins Phospholipid Builtonaglycerolbackbone OneormoreFA Phosphorusgroup Nitrogenousbase Phospholipids Foundinbody,cellstructures Synthesizedbythebodyasneededliver Notneededindiet,notessen2al 13 8/25/09 Glycolipids Fa^yacidboundwithcarbohydrateandnitrogen Essen2alpartofcellmembranes Glycolipids Lipoproteins Proteinsjoinedwithtriacylglycerolsor phospholipids Primarylipidtransport CompoundLipidsLipoproteins 14 8/25/09 Lipoproteins Lipoproteins Chylomicrons Lipoproteinlipase Musclefa^yacids Adipose2ssuereformtriglycerides Lipolysis 15 8/25/09 Triglyceridesintramuscular VLDL Lipoproteins Transportofsynthesizedlipids Cholesterol,TGinwatersolubleshell LDL Remainingcholesteroldense HDL Highpropor2onofprotein Func2onsofLipids Fuel Protectsvitalorgans Helpstransportfatsolublevitamins Importantcons2tuentofcellmembranes Cholesterolimportantinforma2onofbile Precursorforhormones LipidasFuel Fa^yacids Intramusculartriacylglycerols(IMTG) Circula2ngplasmatriacylglycerols Chylomicrons VLDL Omega3,6 Suppresseshunger,tastesgood 16 ...
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