1. Energy Balance Susan Algert

2. Indirect calorimetry • Measuring energy use without measuring heat production • O2 uptake and CO2 output • Doubly labeled water method • Gas exchange

3. Bomb Calorimeter • Energy is released in form of heat when food is burned. • The amount of heat generated provides a direct measure of the amount of energy stored in the food’s chemical bonds. • Direct versus indirect calorimetry

4. Appetite, Hunger, Satiety • Hunger—physiological response to a need for food triggered by chemical messengers in the brain • Appetite-response to sight, smell, taste of food that initiates or delays eating • Satiety—The feeling of satisfaction that occurs after a meal

5. Factors influencing eating • Physiological • Sensory • Cognitive • Postingestive and Postabsorptive influences

6. Components of Energy Expenditure • Basal Metabolism • Physical Activity • Thermic Effect of Food • Adaptive Thermogenesis

7. Factors that Affect BMR-increase or decrease? • Age • Height • Growth • Body Composition • Fever • Stresses

8. Resting Energy Expenditure • Harris Benedict equation used to calculate REE based on person’s age, weight, height and sex.

9. Energy Expenditure of Organs in adult • Brain—19% of REE • Liver—29% of REE • Heart—10% of REE • Skeletal Muscles—18% of REE

10. Factors that affect BMR • Environmental temperature • Fasting/starvation • Malnutrition • Hormones • Smoking • Caffeine • Sleep

11. Healthy Body Weight • Tables • BMI • Overweight • Underweight • Body composition

12. Assessing Body Fat • Densiometry such as underwater weighing • Dual energy x-ray absorptiometry • Skinfold thickness • Bioelectrical impedance analysis • CT and MRI

13. Health Risks Associated with Body Weight • Hypertension • Heart Disease and Stroke • Diabetes • Cancer • Sleep Apnea • Osteoarthritis • Gout

14. Current Thinking on Obesity • Obesity gene codes for protein leptin • Produced by fat cells • Leptin acts as a hormone • Promotes negative energy balance

15. White versus Brown Adipose Tissue • White adipose tissue stores fat for other cells to use for energy • Brown adipose tissue releases stored energy as heat

16. Neuropeptide Y • Neurotransmitter produced in the brain • Stimulates appetite • Diminishes energy expenditure • Increases fat storage

17. Dietary fat promotes obesity because • It is palatable • It produces little satiety • It provides 9 kcals per gram • Increases body fat stores in excess

18. Components of successful weight loss • Low fat diet; cut back one fourth to one third on calories • Activity; 250cals/day, 5-6 X/wk • Behavior Modification including food records • Be realistic

19. Drugs and Surgery for Obesity • Prescription • Over the counter • Surgery

20. Weight Gain • Takes time • Eat energy dense foods • Eat snacks • Exercise to eat and gain muscle—strength training and an extra 700-1,000 calories per day