Energy expenditure differs between Black and White Americans: Implications for obesity prevention research

Our objective was to assess differences in energy expenditure by race and ethnicity, given our hypothesis that persons with lower resting energy expenditure will accrete bodyweight more readily and therefore rates of obesity should be higher in Blacks than in Whites. We used NHANES 2003-2004 to analyze a sample of 4655 US adults. Energy intake (EI) was taken to be the quantity of kilocalories reportedly consumed by participants on day 1 of the dietary intake examination. Voluntary energy expenditure (VEE) was estimated on the basis of accelerometers worn by participants. Intensity of activity was assessed by recording accelerations executed each minute by wearers of the device. We used the equation developed by Yngve and colleagues to convert accelerations per minute into metabolic equivalents (METs). We confirmed that Blacks exhibit lower resting energy expenditure than Whites—a difference of approximately 150 to 300 fewer kilocalories per day. This finding was significant in each permutation of our analysis—from the simple association of race and resting energy expenditure to our final regression model adjusted for common confounders (i.e. age, gender, income, and education), body fat content, diabetes, thyroid dysfunction, and weight loss in previous year. Our findings suggest that if rates of obesity are to be reduced in African Americans, recommendations would need to encourage lower levels of average energy intake and higher levels of activity energy expenditure than extant in the general populace. African Americans would need to adopt more austere lifestyle regimens relative to the general populace in order to reduce their obesity rate below present levels.