Effects of ginger intervention on anthropometric and body composition indices in patients with type 2 diabetes: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials

Background and aims Evidence on the effects of ginger supplementation on anthropometric and body composition indices in adults with type 2 diabetes mellitus (T2DM) is inconsistent, and the certainty of this evidence has not been fully evaluated. This study aimed to systematically review and meta-analyze randomized controlled trials assessing these effects. Methods PubMed, Scopus, and Web of Science were searched until October 5, 2025. We used random-effects meta-analysis to find average differences with 95% CIs. Study quality and evidence certainty were checked with Cochrane RoB-2 tool and GRADE approach. Subgroup, meta-regression, sensitivity, and publication bias analyses were also done. Results This meta-analysis included 692 participants from 12 RCTs. Ginger supplementation significantly reduced body mass index ( BMI) (− 0.24 kg/m²; 95% CI: −0.48, − 0.00; p = 0.043) and body fat percentage (BF%) (− 1.44%; 95% CI: −2.49, − 0.38; p = 0.007), while no significant effects were observed on body weight (BW), waist circumference (WC), hip circumference (HC), or waist-to-hip ratio (WHR). Bias assessment showed 9 studies with some concerns, 1 low, and 2 high risk. Evidence quality was moderate for 4 outcomes (BMI, WHR, HC, BF%), low for WC, and high for BW. Conclusion Ginger reduced BMI and BF%, with no significant change in BW, WHR, HC, or WC. Trial registration This study was prospectively registered in PROSPERO (CRD420251162956).