Effects of omega-3 supplementation on body weight and body fat mass: A systematic review

Clin Nutr ESPEN. 2021 Aug;44:122-129. doi: 10.1016/j.clnesp.2021.04.023. Epub 2021 May 19.


Background: Omega-3 is a supplement that promotes several health benefits. The evidence on omega-3 in weight loss or body fat mass is inconclusive. This study aimed to review the literature on studies that evaluated the effect of omega-3 supplementation and changes in weight and/or body fat mass in humans.

Methods: A systematic review, following the recommendations of PRISMA, in the databases Pubmed, Lilacs, and Scielo. Only experimental studies in humans that evaluated the effects of supplementation with omega-3 on weight loss and/or body fat mass were included.

Results: In total, 20 studies were selected, of which 11 found no effect, and the other nine find some benefits. Two studies found a reduction in individuals' body fat, and a third found these results in women and a fourth only in men. In children and adolescents, one study found a difference in weight loss between groups. Four studies reported decreased body weight in women, and in men, only one found this result.

Conclusion: To date, there is no consistency in the literature that omega-3 has benefits in weight loss or body fat mass in humans. Due to the studies' heterogeneity and inconsistency in the results, further studies on the subject are necessary.

Keywords: Body fat mass; Fish oil; Omega-3; Weight loss.

Publication types

  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Adipose Tissue
  • Adolescent
  • Body Weight
  • Child
  • Dietary Supplements
  • Fatty Acids, Omega-3*
  • Female
  • Humans
  • Male


  • Fatty Acids, Omega-3

Associated data

  • IRCT/2016102530489N1