Darcy L Johannsen1, Kara L Marlatt1, Kevin E Conley2, Steven R Smith3, Eric Ravussin1. 1. Clinical Science, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. 2. Department of Radiology, Bioengineering, Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA. 3. Translational Research Institute for Metabolism and Diabetes, Advent Health, Orlando, FL 32827, USA.
Abstract
BACKGROUND: A metabolic adaptation, defined as an increase in energy expenditure (EE) beyond what is expected with weight gain during overfeeding (OF), has been reported but also refuted. Much of the inconsistency stems from the difficulty in conducting large, well-controlled OF studies in humans. OBJECTIVES: The primary aim of this study was to determine whether a metabolic adaptation to OF exists and if so, attenuates weight gain. METHODS: Thirty-five young adults consumed 40% above their baseline energy requirements for 8 wk, and sleeping metabolic rate (SMR) and 24-h sedentary energy expenditure (24h-EE) were measured before and after OF. Subjects were asked to return for a 6-mo post-OF follow-up visit to measure body weight, body composition, and physical activity. RESULTS: After adjusting for gains in fat-free mass and fat mass, SMR increased by 43 ± 123 kcal/d more than expected (P = 0.05) and 24h-EE by 23 ± 139 kcal/d (P = 0.34), indicating an overall lack of metabolic adaptation during OF despite a wide variability in the response. Among the 30 subjects who returned for the 6-mo follow-up visit, those who had a lower-than-predicted SMR (basal EE) retained more of the fat gained during OF. Likewise, subjects displaying a higher-than-predicted sedentary 24h-EE lost significantly more fat during the 6-mo follow-up. CONCLUSIONS: Metabolic adaptation to OF was on average very small but variable between subjects, revealing "thrifty" or "spendthrift" metabolic phenotypes related to body weight loss 6 mo later. This trial was registered at clinicaltrials.gov as NCT01672632.
BACKGROUND: A metabolic adaptation, defined as an increase in energy expenditure (EE) beyond what is expected with weight gain during overfeeding (OF), has been reported but also refuted. Much of the inconsistency stems from the difficulty in conducting large, well-controlled OF studies in humans. OBJECTIVES: The primary aim of this study was to determine whether a metabolic adaptation to OF exists and if so, attenuates weight gain. METHODS: Thirty-five young adults consumed 40% above their baseline energy requirements for 8 wk, and sleeping metabolic rate (SMR) and 24-h sedentary energy expenditure (24h-EE) were measured before and after OF. Subjects were asked to return for a 6-mo post-OF follow-up visit to measure body weight, body composition, and physical activity. RESULTS: After adjusting for gains in fat-free mass and fat mass, SMR increased by 43 ± 123 kcal/d more than expected (P = 0.05) and 24h-EE by 23 ± 139 kcal/d (P = 0.34), indicating an overall lack of metabolic adaptation during OF despite a wide variability in the response. Among the 30 subjects who returned for the 6-mo follow-up visit, those who had a lower-than-predicted SMR (basal EE) retained more of the fat gained during OF. Likewise, subjects displaying a higher-than-predicted sedentary 24h-EE lost significantly more fat during the 6-mo follow-up. CONCLUSIONS: Metabolic adaptation to OF was on average very small but variable between subjects, revealing "thrifty" or "spendthrift" metabolic phenotypes related to body weight loss 6 mo later. This trial was registered at clinicaltrials.gov as NCT01672632.
Authors: Darcy L Johannsen; Nicolas D Knuth; Robert Huizenga; Jennifer C Rood; Eric Ravussin; Kevin D Hall Journal: J Clin Endocrinol Metab Date: 2012-04-24 Impact factor: 5.958
Authors: S B Roberts; V R Young; P Fuss; M A Fiatarone; B Richard; H Rasmussen; D Wagner; L Joseph; E Holehouse; W J Evans Journal: Am J Physiol Date: 1990-09