The effect of total and partial meal replacements on obesity: a systematic review and meta-analysis of randomized controlled trials

The objective of this study was to conduct a comprehensive investigation into the effects of MRs on body weight, body mass index (BMI), fat mass, waist circumferences (WC), and leptin. A systematic search was conducted in five databases using established keywords. The random-effects model analysis was used to provide pooled weighted mean difference and 95% confidence intervals (CI). Seventy studies were included in this article. The pooled findings showed that body weight (WMD: −3.35 kg, 95% CI: −4.28 to −2.42), BMI (WMD: −1.12 kg/m², 95% CI: −1.51 to −0.72, <i>p</i> &lt; 0.001), fat mass (WMD: −2.77 kg, 95% CI: −3.59 to −1.6), WC (WMD: −2.82 cm, 95% CI: −3.51 to −2.12) were significantly reduced after total and partial MRs compared to control group. However, no significant effect was observed on leptin (WMD: −3.37 ng/mL, 95% CI: −8.23 to 1.49) compared to the control group. Moreover, subgroup analyses indicated that impact of Total MRs on anthropometric factors was greater in comparison to Partial MRs. Consequently, it appears that MRs, along with other lifestyle factors, can lead to significant weight loss.