ABSTRACT
Metabolic Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 Thermic Effect of Food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 Resting Metabolic Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Body Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Gender and Race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 Calorie-Restricted Diets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Diet and Exercise Interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Exercise Energy Expenditure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 Energy Costs of Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 Postexercise Energy Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Determining Energy Intake and Expenditure . . . . . . . . . . . . . . . . . . . . . . . . 201 Assessing Energy Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Assessing Energy Expenditure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Direct Calorimetry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Indirect Calorimetry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Predicting Resting Energy Expenditure . . . . . . . . . . . . . . . . . . . . . 205 Predicting Exercise Energy Expenditure . . . . . . . . . . . . . . . . . . . . 205
Exercise Energy Needs for the Previously Obese Patient . . . . . . . . . . . . . . . 206 Exercise Energy Needs for the Anorexic Patient . . . . . . . . . . . . . . . . . . . . . 206 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
The 24-h energy expenditure can be broken down into three components, the thermic effect of food, the resting metabolic rate, and the energy cost of physical activity (Figure 12.1). The thermic effect of food is defined as the amount of
energy required to digest, absorb, and further process the energy-yielding nutrients in food (i.e., fat, protein, carbohydrate). These energy-expending processes for preparing food prior to its use in intermediary metabolism generate heat, and are therefore collectively called the thermic effect of food (TEF) or, alternatively, diet-induced thermogenesis. The contribution of the TEF to the 24-h energy expenditure is minimal, and ranges from 5 to 10%. Given a daily energy expenditure of 2500 kcal (10.46 MJ), the TEF would be between 125 and 250 kcal (523 and 1046 kJ).
