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-lowcalorie 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: 28.2 kg and VLCD: 29.0 kg, P 5 0.24). Weight regain after follow-up was not significantly different between groups (LCD: 4.2 kg and VLCD: 4.5 kg, P 5 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 5 0.034) and was associated with weight regain during follow-up in the whole group (r 5 0.325, P 5 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.

Weight regain after successful weight loss is a big problem in obesity management. This study aimed to investigate whether weight regain after a weight loss period is correlated with the macronutrient composition and/or the inflammatory index of the diet during that period. Sixty one overweight and obese adults participated in this experimental study. Subjects lost approximately 10% of their initial weight by means of very low-calorie diet for five weeks, or a low calorie diet for 12 weeks. After that, subjects in both groups followed a strict weight maintenance diet based on individual needs for four weeks, which was followed by a nine-month weight maintenance period without dietary counseling. Anthropometrics and dietary intake data were recorded before weight loss (baseline) and during the weight maintenance period. On average, participants regained approximately half of their lost weight. We found no evidence that macronutrient composition during the weight maintenance period was associated with weight regain. The dietary inflammatory index (r = 0.304, p = 0.032) was positively correlated with weight regain and remained significant after correction for physical activity (r = 0.287, p = 0.045). Our data suggest that the inflammatory properties of diet play a role in weight regain after weight loss in overweight and obese adults.