Efficacy of omega-3 polyunsaturated fatty acids supplementation in managing overweight and obesity: A meta-analysis of randomized clinical trials

Studies in rodents and humans have indicated that omega-3 polyunsaturated fatty acids (n-3 PUFA) may reduce weight. The aim of this meta-analysis was to evaluate evidence for the efficacy of n-3 PUFA in managing overweight and obesity. We performed a systematic search of PubMed, Embase, and Cochrane Central Register of Controlled Trials until May 2015. Two reviewers independently determined the eligibility of studies and assessed the reporting quality of included randomized controlled trials (RCTs). A total of 11 RCTs involving 617 participants were included in this meta-analysis. Based on the meta-analysis of nine studies, a statistically nonsignificant difference was revealed in weight loss between n-3 PUFA and placebo (p=0.99; weighted mean difference [WMD]: 0.00; 95% confidence interval [CI] -0.42 to 0.43), whereas n-3 PUFA was superior to placebo in reducing serum triglyceride levels (p=0.0007; standard median difference [Std MD]: -0.59; 95% CI -0.93 to -0.25). Based on meta-analysis of seven studies, the analysis of aggregated data showed a significant reduction in waist circumference (p=0.005; WMD: -0.53; 95% CI -0.90 to -0.16). There were no significant differences in body mass index, total serum levels of cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and fasting glucose levels. The evidence from RCTs showed that n-3 PUFA might effectively reduce waist circumference and triglyceride levels in overweight and obese adults, but n-3 PUFA may not effectively reduce body weight. Given the small number and poor quality of RCTs included in the meta-analysis, these results are inconclusive. A large-scale, well-designed RCT is needed to further address this issue..