The Effects of Bitter Melon (Mormordica charantia) on Weight Loss and Body Composition: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Abstract

Results from the clinical research about Momordica charantia (MC) benefits on weight loss have been contradictory. This study, which included the most available randomized placebo-controlled trials (RCTs), was the first to investigate the impact of MC supplementation on body weight and composition. The effects of the given MC on weight, body mass index (BMI), waist circumference (WC), and percentage of body fat (PBF) were examined in RCTs up to February 2023 (without limitation on release date). Online databases (PubMed/Medline, Google Scholar, Scopus, and Web of Science) were searched for these studies. The inclusion and exclusion criteria were followed in the screening and evaluation of the literature. The Cochrane tool was used to assess bias risk. There were a total of ten RCTs, including 448 participants. The meta-analysis revealed that MC supplementation had no effect on weight (weighted mean difference (WMD): 0.04 kg; 95% confidence interval ([CI]: −0.16 to 0.25; p = 0.66), BMI (WMD: −0.18 kg/m²; 95% CI: −0.43 to 0.25; p = 0.16), WC (WMD: −0.94 cm; 95% CI: −3.04 to 1.16; p = 0.37), and BFP (WMD: −0.99; 95% CI: −2.33 to 0.35; p = 0.14). According to the subgroup analysis, MC could lower the BMI at a dosage of ≤ 2000 mg/d when compared to a placebo group (p<0.001). The dose-response analysis represented a significant nonlinear connection between the MC dosage and weight reduction (P_{non−linearity} = 0.011); the effect on weight loss was observed the most at doses of 2000 and 4500 mg. Moreover, MC consumption decreased the BMI by the sixth week and then increased the BMI up to the 17th week (P_nonlinearity = 0.03). Our results indicate that MC consumption can reduce the BMI in some dosages and duration of supplementation.