Chlorogenic acid in green bean coffee on body weight: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND: Supplemental green bean coffee extract (GBCE) with caffeine has been shown to prevent weight gain. There are different dosages of GBCE that contain chlorogenic acid (CGA), and the data for their effectiveness in preventing weight gain (500 mg/day) is currently out of date. To better understand the effects of GBCE containing CGA on body weight, the present study sets out to perform a systematic review and meta-analysis of these studies. METHODS: Using electronic databases, including Scopus, Embase, PubMed, and Cochrane Library databases, literature was searched up to October 13, 2022. For the meta-analysis examining the impact of GBCE containing CGA (500 mg/day) on body weight with a random-effects model, the randomized controlled trials (RCTs) were considered. We calculated weighted mean differences and 95% confidence intervals (CIs). To gauge study heterogeneity, the Cochran Q statistic and I-squared tests (I(2)) were employed. RESULTS: The meta-analysis includes three RCTs with 103 individuals (case = 51, control = 52). The combined findings of GBCE with CGA at least 500 mg/day result in body weight reduction (WMD: − 1.30 and 95% CI: − 2.07 to − 0.52, p = 0.001) without study heterogeneity (I(2) = 0%, p = 0.904) and without publication bias estimated using Egger’s and Begger’s test (p = 0.752 and p = 0.602, respectively). CONCLUSIONS: According to the meta-analysis, GBCE with CGA 500 mg/day lowers body weight. Nevertheless, despite its limited sample size and short-term study, this study was successful. Long-term research on the effectiveness and safety of GBCE and CGA on body weight require more clinical trials. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021254916. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13643-023-02311-4.