DIETARY ENERGY-REQUIREMENTS OF YOUNG-ADULT MEN, DETERMINED BY USING THE DOUBLY LABELED WATER METHOD

We examined the hypothesis that current recommendations on dietary energy requirements may underestimate the total energy needs of young adult men, by measuring total energy expenditure (TEE) and resting energy expenditure (REE) in 14 weight-maintaining healthy subjects leading unrestricted lives. TEE and body composition were measured by using H-2(2) O-18, and REE was measured by using indirect calorimetry. All subjects had sedentary full-time occupations and participated in strenuous leisure activities for 34 +/- 6 (SE) min/d. TEE and REE were 14.61 +/- 0.76 and 7.39 +/- 0.26 MJ/d, respectively, and 202 +/- 2 and 122 +/- 2 kJ.kg-1.d-1. There were significant relationships between TEE and both body fat-free mass (r = 0.732, P < 0.005) and measured REE (r = 0.568, P < 0.05). Measured TEE:REE values were significantly higher than the recommended energy requirement (1.98 +/- 0.09, compared with 1.55 or 1.67, P < 0.005). These results are consistent with the suggestion that the current recommended energy intake for young adult men may underestimate total energy needs.