Quantifying the Persistence of Metabolic Adaptation and Weight Regain Following Extreme Weight Loss

Weight loss is accompanied by a slowing of metabolic rate. Metabolic slowing often occurs to a degree greater than predicted by the amount of weight lost, a phenomenon called metabolic adaptation , and is hypothesized to persist over time and promote weight regain. We previously discovered large metabolic adaptations in response to the intensive lifestyle intervention as part of The Biggest Loser weight loss competition. Those subjects rapidly lost massive amounts of weight and their resting energy expenditure decreased by \~500 kcal/d more than was expected based on their body composition at the end of the intervention. The purpose of this study is to investigate whether the metabolic adaptation has persisted in the years following the intervention in the same subjects. Furthermore, we will measure body weight and composition in these subjects and investigate the correlates of weight regain.