Persistent metabolic adaptation 6 years after “The Biggest Loser” competition

Abstract

This study examined resting metabolic rate in adolescent wrestlers to test the hypothesis that repeated cycles of weight loss and regain would be associated with reduced energy requirements. Energy restriction lowers resting metabolic rate in normal-weight and obese persons. Repeated cycles of weight loss and regain can increase food efficiency, defined as the degree of weight change per unit of food intake, in animals. Many wrestlers lose weight repeatedly as they "cut weight" for matches. This cycle of weight loss and regain may affect their resting metabolism. Twenty-seven wrestlers were classified as cyclers or non-cyclers based on their weight loss history. Resting metabolic rate was measured using indirect calorimetry and body composition was evaluated using six skinfolds. Cyclers and noncyclers did not differ in age, weight, height, surface area, lean body mass, or percent body fat. Cyclers had a significantly lower mean resting metabolic rate than noncyclers (154.6 vs 177.2 kJ/m2/h) (4.6 vs 5.5 kJ per kilogram of lean body mass per hour). There was a 14% difference between the cyclers and the noncyclers in resting energy expenditure (6631.8 vs 7702.8 kJ/d). Weight cycling in wrestlers appears to be associated with a lowered resting metabolic rate.