Does indirect calorimetry measure total energy expenditure?

Does indirect calorimetry measure total energy expenditure?

• A. Yes
• B. No
• C. Only when glucose infusion
• D. Sometimes

Answer: (B)

Indirect calorimetry estimates energy expenditure from gas exchange (oxygen used and carbon dioxide produced) during the measurement period. It yields the metabolic rate for that specific time, usually at rest and in a controlled state, which is resting energy expenditure. Total daily energy expenditure, however, includes resting energy, the thermic effect of food, and energy expended through activity. Indirect calorimetry on its own doesn’t capture all of those components in free-living conditions, so it does not measure total energy expenditure. If you measure over a full 24 hours in a metabolic chamber you could estimate TEE, but standard indirect calorimetry is used for resting (or steady-state) energy expenditure, not total daily expenditure.

Indirect calorimetry estimates energy expenditure from gas exchange (oxygen used and carbon dioxide produced) during the measurement period. It yields the metabolic rate for that specific time, usually at rest and in a controlled state, which is resting energy expenditure. Total daily energy expenditure, however, includes resting energy, the thermic effect of food, and energy expended through activity. Indirect calorimetry on its own doesn’t capture all of those components in free-living conditions, so it does not measure total energy expenditure. If you measure over a full 24 hours in a metabolic chamber you could estimate TEE, but standard indirect calorimetry is used for resting (or steady-state) energy expenditure, not total daily expenditure.