Persistent metabolic adaptation 6 years after “The Biggest Loser” competition
See Commentary: , pg. 1609.
Funding agencies: : This research was supported by the Intramural Research Program of the NIH, National Institute of Diabetes and Digestive and Kidney Diseases.
Disclosure: : The authors declared no conflict of interest.
Clinical trial registration: : ClinicalTrials.gov identifier NCT02544009.
Abstract
Objective
To measure long‐term changes in resting metabolic rate (RMR) and body composition in participants of “The Biggest Loser” competition.
Methods
Body composition was measured by dual energy X‐ray absorptiometry, and RMR was determined by indirect calorimetry at baseline, at the end of the 30‐week competition and 6 years later. Metabolic adaptation was defined as the residual RMR after adjusting for changes in body composition and age.
Results
Of the 16 “Biggest Loser” competitors originally investigated, 14 participated in this follow‐up study. Weight loss at the end of the competition was (mean ± SD) 58.3 ± 24.9 kg (P < 0.0001), and RMR decreased by 610 ± 483 kcal/day (P = 0.0004). After 6 years, 41.0 ± 31.3 kg of the lost weight was regained (P = 0.0002), while RMR was 704 ± 427 kcal/day below baseline (P < 0.0001) and metabolic adaptation was −499 ± 207 kcal/day (P < 0.0001). Weight regain was not significantly correlated with metabolic adaptation at the competition's end (r = −0.1, P = 0.75), but those subjects maintaining greater weight loss at 6 years also experienced greater concurrent metabolic slowing (r = 0.59, P = 0.025).
Conclusions
Metabolic adaptation persists over time and is likely a proportional, but incomplete, response to contemporaneous efforts to reduce body weight.
