Free-Living Responses in Energy Balance to Short-Term Overfeeding in Adults Differing in Propensity for Obesity.

Abstract

Free-living adaptive responses to short-term overfeeding (OF) were explored as predictors of longitudinal weight change in adults classified as having obesity resistance (OR) or obesity proneness (OP) based on self-identification and personal/family weight history. Adults identified as OP (n = 21; BMI: 23.8 ± 2.5 kg/m² ) and OR (n = 20; BMI: 20.2 ± 2.1 kg/m² ) completed 3 days of eucaloric feeding (EU; 100% of energy needs) and 3 days of OF (140% of energy needs). Following each condition, adaptive responses in physical activity (PA), total daily energy expenditure, ad libitum energy intake, and energy balance were objectively measured for 3 days in a free-living environment. Body mass and composition were measured annually by using dual-energy x-ray absorptiometry for 5 years. Adaptive responses to OF were correlated with 5-year changes in body mass and composition. Increases in sedentary time correlated with longitudinally measured changes in fat mass (r = 0.34, P = 0.04) in the cohort taken as a whole. Those with OP reduced their levels of PA following OF, whereas those with OR maintained or increased their PA. No other variables were found to correlate with weight gain. Failure to decrease sedentary behavior following short-term OF is one mechanism that may be contributing to fat mass gain.