This study aimed to summarize earlier randomized controlled trials on the effects of resveratrol supplementation on body weight (BW), body mass index (BMI), waist circumference (WC) and fat mass (FM). We searched PubMed, SCOPUS, Cochrane Library and Google Scholar from inception to April 2018 using relevant keywords. All clinical trials investigating the effects of resveratrol supplementation on BW, BMI, WC and FM in adults were included. Overall, 28 trials were included. Pooled effect sizes suggested a significant effect of resveratrol administration on weight (weighted mean differences [WMD]: À0.51 kg, 95% confidence interval [CI]: À0.94 to À0.09; I 2 = 50.3%, P = 0.02), BMI (WMD: À0.17 kg m À2 , 95% CI: À0.32, À0.03; I 2 = 49.6%, P = 0.02) and WC (WMD: À0.79 cm, 95% CI: À1.39, À0.2; I 2 = 13.4%, P = 0.009), respectively. However, no significant effect of resveratrol supplementation on FM was found (WMD: À0.36%, 95% CI: À0.88, 0.15; I 2 = 0.0%, P = 0.16). Findings from subgroup analysis revealed a significant reduction in BW and BMI in trials using resveratrol at the dosage of <500 mg d À1 , those with long-term interventions (≥3 month), and performed on people with obesity. Taken together, the data suggest that resveratrol supplementation has beneficial effects to reduce BW, BMI and WC, but not FM.