Measurement of resting energy expenditure in infants

Abstract

Objective: The method for measurement of basal metabolic rate (BMR) using indirect calorimetry in adults is well established but is impractical in infants. Methods: In this prospective study energy expenditure was measured using indirect calorimetry in 14 infants when sleeping and when lying quietly awake. Results: Sleeping metabolic rate (SMR) was lower than energy expenditure (EE) measured in the same infants in a quiet resting state (mean difference [SD]: 297 [162] kJ/d; P < 0.005; 55 [33.4] kJ/kg per day; P < 0.005). The correlation within individuals suggests that these differences are related to the level of arousal. Awake EE, but not SMR, was significantly greater than estimated BMR u..