Familial Dependence of the Resting Metabolic Rate

Abstract

Human obesity is known to be a familial disorder. We studied 130 nondiabetic adult southwestern American Indians (74 men and 56 women) from 54 families to determine whether the resting metabolic rate, as measured by indirect calorimetry, is a familial trait that is independent of individual differences in fat-free mass (estimated mass of metabolically active tissue), age, and sex. We found that most of the variance in the resting metabolic rate (83 percent, P<0.0001) was accounted for by three covariates — fat-free mass, age, and sex — and that fat-free mass was the most important determinant. Family membership accounted for an additional 11 percent (P<0.0001) of the variance in the resting metabolic rate. Thus, resting metabolic rate is a familial trait in this population, and it is independent of differences in fat-free mass, age, and sex.