The effect of green tea supplementation on the anthropometric outcomes in overweight and obese women: a time and dose-response meta-analysis of randomized controlled trials

Inconsistencies are evident within the literature regarding the role of Green Tea (GT) supplementation on women living with obesity. To address this, we conducted to determine the impact of GT supplementation on the weight, body mass index (BMI), and waist circumference (WC) in overweight and obese women using time and dose-response meta-analysis of randomized controlled trials (RCTs). This meta-analysis searched electronic Scopus, Web of Science, Embase, and PubMed/Medline databases from inception to December 1st, 2022. Data were reported as weighted mean difference (WMD) with 95% confidence interval (CI). A total of 2061 references were identified, and 15 articles with 16 RCT arms on body weight, 17 RCT arms on BMI, and 7 RCT arms on WC were included in the meta-analysis. GT supplementation significantly decreases body weight (WMD: −1.23 kg, 95% CI: −2.13 to −0.33, p = 0.007), BMI (WMD: −0.47 kg/m2, 95% CI: −0.87 to −0.07, p = 0.020) and WC (WMD: −3.46 cm, 95% CI: −6.75 to −0.16, p = 0.040). In subgroup analyses, GT consumption demonstrated lowered body weight with dosaes ≥1000 mg/day (WMD: −1.38 kg), in the RCTs, which lasted ≥8 wk (WMD: −1.24 kg). The non-linear dose-response assessment detected a negative correlation between the changes in body weight and BMI in green tea consumption of more than 1000 (mg/day). The GT supplementation reduced the weight, BMI, and WC in overweight and obese women. In clinical practice, healthcare professionals can recommend using GT with dosages ≥ 1000mg/day and duration ≥ 8 wk in obese women.

目前已有文献中，关于绿茶（Green Tea, GT）补充剂对肥胖女性的作用存在诸多不一致之处。为解决这一问题，本研究通过对随机对照试验（randomized controlled trials, RCTs）进行时间与剂量反应元分析，旨在探究绿茶补充剂对超重及肥胖女性体重、体质指数（body mass index, BMI）及腰围（waist circumference, WC）的影响。本元分析检索了自建库至2022年12月1日期间，Scopus、Web of Science、Embase及PubMed/Medline电子数据库中的相关文献。研究数据以加权均数差（weighted mean difference, WMD）联合95%置信区间（confidence interval, CI）的形式呈现。最终共检索到2061篇相关文献，最终纳入15篇文献，包含16个针对体重的随机对照试验组、17个针对体质指数的随机对照试验组以及7个针对腰围的随机对照试验组用于本次元分析。分析结果显示，绿茶补充剂可显著降低超重及肥胖女性的体重（加权均数差：−1.23 kg，95%置信区间：−2.13至−0.33，p = 0.007）、体质指数（加权均数差：−0.47 kg/m²，95%置信区间：−0.87至−0.07，p = 0.020）及腰围（加权均数差：−3.46 cm，95%置信区间：−6.75至−0.16，p = 0.040）。亚组分析结果表明，在每日剂量≥1000mg的随机对照试验中，以及持续时长≥8周的随机对照试验中，饮用绿茶可显著降低体重（加权均数差分别为−1.38 kg与−1.24 kg）。非线性剂量反应分析显示，当日均绿茶摄入量超过1000mg时，体重与体质指数的变化呈负相关关系。综上，绿茶补充剂可有效降低超重及肥胖女性的体重、体质指数与腰围。在临床实践中，医疗工作者可推荐肥胖女性每日服用≥1000mg剂量、持续时长≥8周的绿茶补充剂。