Energy Balance and Body Composition

Studying = 1 or 2 kcalories/minute

Energy Balance

Food Composition

• Direct calorimetry vs. indirect calorimetry

• Physiological fuel value

Food Intake • Hunger• Appetite• Satiation• Satiety• Overriding hunger and satiety

– Stress eating• Sustaining satiation and satiety

– satiating

Food Intake

• Sustaining satiation and satiety– lower-fat foods can be eaten in

larger portions for the same number of kcalories

Food Intake

Food Intake

• Hypothalamus– Neuropeptide Y

Thermogenesis

• Basal thermogenesis

• Exercise-induced thermogenesis

• Diet-induced thermogenesis

• Adaptive thermogenesis

Components of Energy Expenditure

Components of Energy Expenditure

• Basal metabolism• Basal metabolic rate (BMR)• Resting metabolic rate (RMR)• Physical activity

Components of Energy Expenditure

• Thermic effect of food (TEF)

• Diet-induced thermogenesis (DIT)

Estimating Energy Requirements

• Gender

• Growth

• Age

Estimating Energy Requirements

• Physical activity

• Body composition

• Body size

Body Weight, Body Composition,

and Health

• Body composition

• Body weight = fat + lean tissue (including water)

Defining Healthy Body Weight

• The criterion of fashion: BMI of Miss America

Defining Healthy Body Weight

• The criterion of health• Body mass index (BMI)

=weight (kg)/height (m)2

BMI Values Used to Assess Weight

Distribution of Body Weights in U.S. Adults

Body Fat and Its Distribution

Body Fat and Its Distribution

• Some people need less body fat

• Some people need more body fat

Body Fat and Its Distribution

• Fat distribution– Intra-abdominal fat– Central obesity

Body Fat and Its Distribution

• Waist circumference-according to some...if it’s anything over 35”, it’s too much!

Body Fat and Its Distribution

• Other measures of body composition– Fatfold measure– Hydrodensitometry– Bioelectrical impedance

Body Fat and Its Distribution

• Other measures of body composition– Air displacement

plethysmography– Dual energy X-ray

absorptiometry (DEXA)

Methods Used to Assess Methods Used to Assess Body FatBody Fat

Health Risks Associated With Body Weight and

Body Fat

• Health risks of underweight

• Health risks of overweight

BMI and Mortality

Health Risks Associated With Body Weight and Body Fat

• Cardiovascular disease• Diabetes• Cancer• Fat and fit versus sedentary and

slim

The Latest and Greatest Weight-Loss Diet - Again

• The claims and truths of diet fads• High-protein, low carbohydrate diets

– The diet’s appeal

The Latest and Greatest Weight-Loss Diet - Again

• High-protein, low carbohydrate diets– Don’t count kcalories– Satisfy hunger– Follow a plan– Limit choices

The Latest and Greatest Weight-Loss Diet - Again

• High-protein, low carbohydrate diets– Too much fat– Too much protein– Too little everything else– The body’s perspective

Questions or Thoughts

• If you have any questions or thoughts please feel free to post them in the Discussion Forum/Board or you can e-mail your instructor