Which statement about calorie expenditure is true?

• A. It refers to calories consumed from foods
• B. It refers to burning calories
• C. It is measured only during sleep
• D. It equals total calories in the body

Answer: (B)

Calorie expenditure is the energy your body uses to power everything it does, from keeping you alive at rest to moving and processing food. The statement that describes it as burning calories is the best fit because expenditure is all about energy being used, not energy being taken in. It includes several components: the energy your body spends just to stay alive (basal metabolic rate), the extra energy used to digest and absorb food (thermic effect of food), and the energy you burn through movement and activity. It isn’t about calories you eat—that would be intake. It isn’t measured only during sleep, since energy is spent during waking hours as well. And it doesn’t equal the total calories in the body, which reflect stored energy, not how much is being used. Understanding this helps you see how energy balance works: calories in versus calories out.