Effects of Dairy Products Consumption on Body Weight and Body Composition Among Adults: An Updated Meta-Analysis of 37 Randomized Control Trials

Scope: Effects of dairy consumption on body weight and body composition have been inconsistently observed in randomized control trials (RCTs). Our meta-analysis aims to systematically evaluate the effects of dairy consumption on body weight and body composition among the adults. Methods and results: We conducted a comprehensive search of the Cochrane Library, PubMed, and Embase databases of the relevant studies from 1966 to Mar 2017 regarding dairy consumption on body weight and body composition including body fat, lean mass, and waist circumference (WC). The summary results are pooled by using a random-effects meta-analysis. Thirty-seven RCTs with 184802 participants are included in this meta-analysis. High dairy intervention increased body weight (0.01, 95% CI: -0.25, 0.26, I-2 = 78.3%) and lean mass (0.37, 95% CI: 0.11, 0.62, I-2 = 83.4%); decreased body fat (-0.23, 95% CI: -0.48, 0.02, I-2 = 78.2%) and WC (-1.37, 95% CI: -2.28, -0.46, I-2 = 98.9%) overall. In the subgroup analysis, we found that consumption of dairy products increases body weight (0.36, 95% CI: 0.01, 0.70, I-2 = 83.1%) among participants without energy restriction. Dairy consumption decreases body weight (-0.64, 95% CI: -1.05, -0.24, I-2 = 60.2%), body fat (-0.56, 95%CI: -0.95, -0.17, I-2 = 66.6%), and waist circumference (-2.18, 95%CI: -4.30, -0.06, I-2 = 99.0%) among the adults with energy restriction. Conclusions: This meta-analysis suggests a beneficial effect of energy-restricted dairy consumption on body weight and body composition. However, high dairy consumption in the absence of caloric restriction may increase body weight.