The effect of rate of weight loss on long-term weight regain in adults with overweight and obesity.

Objective: To investigate the effect of rate of weight loss, with similar total weight loss, on weight regain in individuals with overweight and obesity.

Methods: Fifty-seven participants (BMI: 28-35 kg/m(2) ) underwent a dietary intervention (DI). They were randomized to a low-calorie diet (LCD; 1250 kcal/day) for 12 weeks (slow weight loss) or a very-low-calorie diet (VLCD; 500 kcal/day) for 5 weeks (rapid weight loss) (weight loss (WL) period) followed by a 4-week weight-stable (WS) period and 9 months follow-up. Body weight and body composition (BodPod) were determined at study start and after each period.

Results: Weight change was similar in both groups after WL (LCD: -8.2 kg and VLCD: -9.0 kg, P = 0.24). Weight regain after follow-up was not significantly different between groups (LCD: 4.2 kg and VLCD: 4.5 kg, P = 0.73). Percentage fat-free mass loss (%FFML) was higher in the VLCD-group compared to the LCD-group after DI (8.8% and 1.3%, respectively, P = 0.034) and was associated with weight regain during follow-up in the whole group (r = 0.325, P = 0.018).

Conclusions: The present study showed that, with similar total weight loss, rate of weight loss did not affect weight regain. However, %FFML after DI was associated with weight regain.