Associations between the rate, amount, and composition of weight loss as predictors of spontaneous weight regain in adults achieving clinically significant weight loss: A systematic review and meta-regression

Weight regain following weight loss is common although little is known regarding the associations between amount, rate, and composition of weight loss and weight regain. Forty-three studies (52 groups; n = 2379) with longitudinal body composition measurements were identified in which weight loss (≥5%) and subsequent weight regain (≥2%) occurred. Data were synthesized for changes in weight and body composition. Meta-regression models were used to investigate associations between amount, rate, and composition of weight loss and weight regain. Individuals lost 10.9% of their body weight over 13 weeks composed of 19.6% fat-free mass, followed by a regain of 5.4% body weight over 44 weeks composed of 21.6% fat-free mass. Associations between the amount (P < 0.001) and rate (P = 0.049) of weight loss and their interaction (P = 0.042) with weight regain were observed. Fat-free mass (P = 0.017) and fat mass (P < 0.001) loss both predicted weight regain although the effect of fat-free mass was attenuated following adjustment. The amount (P < 0.001), but not the rate of weight loss (P = 0.150), was associated with fat-free mass loss. The amount and rate of weight loss were significant and interacting factors associated with weight regain. Loss of fat-free mass and fat mass explained greater variance in weight regain than weight loss alone.