1. Metabolism

2. Feasting Feasting adds to body stores of carbohydrate and fat
Excess carbohydrate  used to fill glycogen stores  excess glucose stored as fat
Excess fat  stored as fat
Excess protein  remove N and store as fat

3. Fasting – Glycogen Available
Draw upon stores during:
fasts (even short-term)
during exercise
Energy stores used:
Carbohydrate – stored as ________________
Fat

4. Fasting – Glycogen Available
Liver glycogen  blood glucose  energy for all cells
Muscle glycogen  muscle glucose  energy for muscle cells
Fat stores  fatty acids in blood  provide energy for all cells, but brain and CNS

5. Fasting – Glycogen Stores EMPTY
Only protein and fats are available as a source of energy
See board!

6. Estimating Energy Needs
Body uses energy for:
Basal metabolism
Thermic effect of food
Physical activity

7. Basal Metabolism Basal metabolism
Energy needed to maintain the body at complete rest (physical, emotional, and digestive)
Largest component of daily energy expenditure

8. Basal Metabolism Basal Metabolic Rate (BMR)
# kcal burned per hour per kg body weight

9. Basal Metabolism BMR impacted by: Lean body mass
More LBM, the higher your BMR
More fat, the lower your BMR
Age and gender (related to LBM)
BMR slows with age
BMR higher in males

10. Basal Metabolism Height Fever raise BMR
Taller, thinner people have a higher BMR
More surface area to support
Fever raise BMR
10 F fever raises BMR by 7%
Fasting and malnutrition lower BMR

11. Basal Metabolism
Smoking and caffeine raise BMR
Stress raises BMR

12. Thermic Effect of Food
TEF – energy needed to digest, absorb, transport, and metabolize nutrients
Smallest component of daily energy expenditure
~ 10% caloric intake

13. Physical Activity
Physical Activity – energy needed to support voluntary activity
Energy required impacted by:
Muscle mass
Body weight
Nature of activity
Duration, intensity, frequency

14. Energy Expenditure Summary
To maintain energy balance, energy input must balance energy expenditure
Expend energy to:
support basal metabolism]
process foods (TEF)
support physical activity