Do African Americans have lower energy expenditure than Caucasians?

OBJECTIVE: To review current studies that examine differences in energy exp enditure between African Americans and Caucasians as possible modulators of attained differences in overweight status. DESIGN: Literature review of recent clinical and laboratory studies. METHODS: Studies chosen for review were those that examined directly restin g metabolic rate (RMR), using indirect calorimetry, and total daily energy expenditure (TDEE) and physical activity energy expenditure (PAEE), using d oubly labeled water. RESULTS: Ten of 15 studies reviewed reported a lower RMR in African America ns than in Caucasians, The differences in RMR between African Americans and Caucasians ranged from 81 to 274 kcal/day and could not be explained by di fferences in age, fat-free mass (FFM) or methodological concerns. Two of si x studies of energy expenditure using doubly labeled water suggest that Bla ck adults have a tendency for lower TDEE that can be accounted for primaril y by a lower PAEE. CONCLUSIONS: If future studies indicate conclusively that African Americans do have lower RMR, TDEE and PAEE than Caucasians, then the disproportional ly higher risk of obesity and associated metabolic disorders in Black adult s may be preventable-especially in Black women. If these race differences a re indeed a result of both physiological and behavioral factors, then inter ventions designed to reduce caloric intake and/or increase energy expenditu re through lifestyle activity or structured exercise programs become especi ally important for African Americans and should be encouraged.