Energy balance slides pdf Su08 - Energy Balance and Body...

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Unformatted text preview: Energy Balance and Body Composition (Studying = 1 - 2 kcalories/minute) Energy Balance Energy In vs Energy Out Energy In Influences: Calories in food Food intake stimuli Energy In Calories in Food Direct calorimetry Physiological fuel value Cal/gm CHO, pro, fat Energy In Food Intake Stimuli Hunger Satiation Satiety Appetite Energy Out Total Energy Expenditure Components: Basal Metabolic Rate (BMR) Thermic Effect of Food (TEF) Activity NEAT (Nonexercise activity thermogenesis) Fig. 9-3, p. 324 Energy Out Total Energy Expenditure TEE = BMR + TEF + activity (+ NEAT) Basal Metabolic Rate BMR All involuntary activity Proportion of TEE Determinants Thermic Effect of Food (TEF) A.k.a.: Diet induced thermogenesis Energy used in food digestion, absorption, transport Estimated at 5-10% of TEE Higher for carbohydrate and protein than for fat Physical Activity/Exercise Most variable of E outputs Dual effect on E output Measuring Energy Output Direct Calorimetry Heat production = energy production Humans direct calorimetry chamber Equivalent to Bomb Calorimeter for food Measuring Energy Expenditure, cont. Indirect Calorimetry Based on the energy metabolism equation: Macronutrients + O2 = ATP + CO2+ H2O States of Energy Balance In balance: E in = E out Positive balance: E in > E out Negative balance: E in < E out Estimating Energy Requirements Gender Growth Age Physical Activity Body Composition Body Size Physiologic State Body weight is the result of energy intake and output over weeks and months Body Weight and Body Composition Body composition Amount of each type of tissue Fat, muscle, other learn tissue, bone Body weight Weight of all tissues What is a healthy weight? Criteria Adequate lean and fat tissues Body mass index (BMI) =weight (kg)/height (m)2 =weight (lb) x 703/height (in)2 Fig. 9-4, p. 330 True or False An athlete who has a high amount of lean mass relative to fat mass might be considered obese by BMI standards. True BMI does not DIRECTLY measure body fat May overestimate or underestimate adiposity Measures of Body Composition Waist circumference Fatfold measurements Hydrodensitometry DEXA Bioelectrical impedance Body Fat and Its Distribution Individual needs for body fat vary Determinants Genetics Gender Fat distribution pattern Apple vs Pear Table 9-3, p. 331 Fig. 9-8, p. 334 Waist Circumference Android adiposity Men > 40 inches Women > 35 inches Health Risks Associated with Fat Distribution Android/Abdominal/apple obesity Diabetes Heart disease Cancer Gynoid/Lower Body/pear obesity Metabolic Fitness Fat and fit versus sedentary and slim Health at any size ...
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This note was uploaded on 07/23/2008 for the course NUTRI SCI 1 taught by Professor Mead during the Summer '07 term at University of California, Berkeley.

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