Effects of Time-Restricted Eating With Calorie Restriction Versus Calorie Restriction on Health Outcomes in Patients With Weight Regain Post-Sleeve Surgery: A Randomized Controlled Trial

PURPOSE: Time-restricted eating (TRE) combined with calorie restriction (CR) has been proposed as a promising approach for weight management after bariatric surgery. Evidence on its effectiveness among patients experiencing weight regain following sleeve gastrectomy remains limited. METHODS: In this 12-week randomized controlled trial, 62 patients with ≥ 10% weight regain two years after sleeve gastrectomy were randomly assigned to a TRE + CR diet (8-hour eating window) or a CR-only diet. Anthropometric, biochemical, and psychological parameters were assessed at baseline and post-intervention. RESULTS: A total of 48 participants (25 in TRE + CR; 23 in CR) completed the trial. Both groups experienced modest, non-significant reductions in body weight and BMI, with significant decreases in waist and hip circumference (p ≤ 0.01). No significant between-group differences were observed in body composition indices. The TRE + CR group showed significant reductions in lean body mass (p = 0.01) and basal metabolic rate (p = 0.003). Fasting blood glucose significantly increased in the TRE + CR group (p < 0.001), whereas lipid and other glycemic indices remained unchanged. Food addiction symptoms and neuroticism scores significantly decreased only in the CR group (p = 0.02 and p = 0.04, respectively). CONCLUSIONS: In patients with post-sleeve weight regain, a 12-week TRE + CR intervention did not produce superior effects compared with CR alone on anthropometric, metabolic, or psychological outcomes. Longer and more comprehensive trials are warranted to determine the optimal dietary approach for sustained weight management after bariatric surgery.