Background/Aims: Dairy contain components that promote fat loss. We conducted a meta-analysis of randomised controlled trials (RCT) in 18-50yr olds investigating effects of dairy during energy restriction on body weight and composition.
Methods: RCT ≥4wks in 18-50yr olds comparing dairy consumption (dairy food & dairy supplements) with control diets lower in dairy during energy restriction on body weight, fat and lean mass were identified by searching MEDLINE (Web of Science), EMBASE, Pubmed, Cochrane Central and WHO ICTRP until June 2014. Multi-component interventions, including those with resistance training, were excluded. Reports were identified and critically appraised in duplicate. Data were pooled using random-effects meta-analysis. I2>50% indicated heterogeneity. Dose effect was assessed using meta-regression analysis. Quality of the body of evidence was rated using GRADE guidelines.
Results: Sixteen RCTs (n=637) were included, all conducted in overweight/obese participants. Consumption of 2-4 standard servings/day of dairy food compared to ≤1 serving/day, or 20-84 g/day of whey protein compared to placebo over median 16 week duration resulted in greater bodyweight loss (mean[95%CI]: -1.21[-1.74,-0.14]kg, P<0.00001, I2=15%) and fat mass loss (-1.41[-2.04,-0.77]kg, P<0.0001, I2=36%). Lean mass was not differentially affected. Dairy food and supplement studies did not differ. No dose-response effect was observed and studies were largely undertaken in women (84%). Quality of evidence was rated as moderate.
Conclusions: Increased dairy intake as part of an energy restricted diet moderately enhanced bodyweight and fat mass loss in 18-50yr olds. Further research is needed to confirm these effects in men.
Funding source: Dairy Health and Nutrition Consortium