A systematic review and meta-analysis on the effects of yoga on weight-related outcomes.

INTRODUCTION

Overweight and obesity are among the most important modifiable risk factors for chronic diseases and premature death. The aim of this review was to systematically assess and analyze the effects of yoga on weight-related outcomes.

METHODS

Medline/PubMed, Scopus, and the Cochrane Library were screened through March 2015 for randomized controlled trials on yoga for weight-related outcomes in the general population or overweight/obese individuals. Risk of bias was assessed using the Cochrane risk of bias tool on the following domains: selection bias, performance bias, detection bias, attrition bias, reporting bias, and other bias.

RESULTS

Out of 445 records identified during literature search, 30 trials with a total of 2173 participants were included. No effects on weight, body mass index, body fat percentage or waist circumference were found. In studies with healthy adult participants an effect of yoga compared to usual care was found regarding waist/hip ratio (SMD=--1.00; 95% CI=--1.44, -0.55; p<0.001). In studies with overweight/obese participants only, effects relative to usual care were found for body mass index (SMD=-0.99; 95% CI=-1.67, -0.31; p=0.004). Effects however were not robust against selection bias; and publication bias could not be ruled out. No intervention-related adverse events were reported.

CONCLUSIONS

Despite methodological drawbacks, yoga can be preliminarily considered a safe and effective intervention to reduce body mass index in overweight or obese individuals.