Background: This systematic review and meta-analysis aimed to investigate the effect of cinnamon on body weight, body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and body fat mass including the maximum number of studies.
Methods: Medline, ISI Web of Science, Scopus, Google Scholar, and Cochrane library were searched with no limitation from inception up to August 2019 for relevant randomized controlled clinical trials (RCTs). The RCTs' risk of bias was assessed using the Cochrane collaboration's tool. Random-effects model was used for meta-analysis.
Results: Twenty-one RCTs with 1,480 participants were included. The meta-analysis showed that cinnamon supplementation significantly reduces BMI [weighted mean difference (WMD) = -0.40 kg/m2 , 95% confidence interval (CI): -0.57, -0.22 kg/m2 , p < .001, I2 = 78.9%], body weight (WMD = -0.92 kg; 95% CI: -1.51, -0.33 kg; p = .002; I2 = 84.2%), and WHR (WMD = -0.02, 95% CI: -0.038, -0.018; p < 0.001; I2 = 0%). Cinnamon supplementation did not significantly affect the WC (WMD = -1.76 cm, 95% CI: -3.57, -0.045 cm; p = .056; I2 = 90.8%) and body fat mass (WMD = -0.87%, 95% CI: -1.87, 0.025%; p = .057; I2 = 78.6%).
Conclusion: Cinnamon supplementation significantly reduces body weight, BMI, and WHR. Future high-quality long-term RCTs are recommended to confirm these results.
Keywords: anthropometric indices; body composition; body weight; cinnamon; meta-analysis; systematic review.
© 2019 John Wiley & Sons, Ltd.