Effects of Resveratrol Supplementation on Metabolic and Anthropometric Outcomes in Non-Alcoholic Fatty Liver Disease: An Umbrella Review and Updated Meta-Analysis

Background:Non-alcoholic fatty liver disease (NAFLD) is strongly associated with dyslipidemia, insulin resistance, chronic inflammation, and abdominal obesity; therefore, NAFLD is considered a major public health concern. This highlights the need for effective early-stage interventions to halt disease progression. However, findings on the effects of resveratrol supplementation in patients with NAFLD have been inconsistent. This comprehensive meta-analysis aimed to synthesize existing evidence to determine the effects of resveratrol supplementation on metabolic and anthropometric outcomes in patients with NAFLD.Method:A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar using relevant keywords, with no date restrictions up to June 2025. Eligible studies were meta analyses published in English. The methodological quality of the included studies and the certainty of the evidence were assessed using the AMSTAR2 scale and the GRADE tool, respectively. Data analysis was performed using Stata version 17 (StataCorp LLC, College Station, Texas, USA).Results:A total of nine meta-analyses were involved in this study, comprising eight randomized controlled trials (RCTs), with a total of 266 patients with NAFLD. The administered resveratrol intervention dose and duration in the included studies ranged from 300 to 3000 mg/day for 8 to 26 weeks. Resveratrol supplementation significantly reduced serum alanine aminotransferase (ALT) levels (weighted mean difference (WMD) = –4.791 IU/L, 95% confidence interval (CI) (–8.823 to –0.759); p = 0.020) and body weight (WMD = –0.666 kg, 95% CI (–1.127 to –0.205); p = 0.005) of patients compared with the control group. In contrast, resveratrol intervention had no significant effects on serum aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT) concentrations, glycemic indices, including fasting blood glucose, and insulin resistance assessed by the homeostasis model; lipid profile parameters, including serum low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglyceride (TG), and total cholesterol (TC) levels; or inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α) levels. Moreover, body mass index (BMI) and central obesity (waist circumference (WC) and waist-to-hip ratio (WHR)) were not significantly altered following resveratrol supplementation.Conclusion:This meta-analysis suggests that resveratrol supplementation may modestly reduce body weight and ALT levels in adults with NAFLD, while exerting no significant effects on glycemic indices, inflammatory, markers, or lipid profiles. Therefore, further high-quality RCTs administration supplementationwith larger sample sizes and standardized dosing regimens are warranted to clarify the clinical benefits of resveratrol intervention in individuals with NAFLD. The PROSPERO Registration: ID number: CRD420251060258 (https://www.crd.york.ac.uk/prospero/).