Effect of Green Tea on Anthropometric Indices and Body Composition in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Aim: Previous studies that investigated the effect of green tea/green tea extract on anthropometric indices among type 2 diabetes mellitus (T2DM) patients found inconsistent results. Thus, in order to clarify the efficacy of green tea supplementation on anthropometric indices and body composition, we conducted a systematic review and meta-analysis to sum up the evidence of randomized controlled trials. Methods: A systematic search was conducted in the Scopus, ISI Web of Science and PubMed to find the related articles, up to June 2019. Meta-analysis was performed using the random effects model, and the I-2 index was used to evaluate the heterogeneity. Results: Eleven articles were eligible. Our meta-analysis indicated that green tea consumption significantly decreased body weight, body mass index (BMI), and body fat (BF). The beneficial effect of green tea intake was observed in long-term intervention (>8 weeks), at lower doses of green tea (dosage <= 800 mg/day), and in overweight patients. Conclusion: This study revealed the beneficial effects of green tea consumption in reducing body weight, BMI, and BF in T2DM patients. It should be noted that green tea was effective in long-term intervention, at lower doses of green tea, and in overweight patients.