ACE Health Coach Certification Practice Test

Which of the following can affect the thermic effect of a meal?

1. calorie count

2. time when eaten

3. macronutrient composition

4. exercising post-consumption

The correct answer is: macronutrient composition

The thermic effect of a meal (TEM) refers to the increase in energy expenditure above the resting metabolic rate that occurs after eating. It is influenced significantly by the macronutrient composition of the meal. Different macronutrients (proteins, fats, and carbohydrates) require varying amounts of energy to digest, absorb, and metabolize. Protein has the highest thermic effect because it takes more energy to process compared to fats and carbohydrates; typically, approximately 20-30% of the calories consumed from protein are used for its metabolism. Carbohydrates generally have a thermic effect of about 5-10%, and fats have the lowest at about 0-3%. Therefore, the specific makeup of a meal in terms of its macronutrient distribution directly impacts how many calories are expended in processing that meal. While calorie count, the timing of the meal, and post-consumption exercise can influence metabolism and energy expenditure, they do not have as direct a relationship with the thermic effect of a meal as the macronutrient composition does. For example, while a higher calorie meal may lead to a greater total energy expenditure due to its size, the efficiency of that energy expenditure is largely determined by what types of calories are