Effects of Long-Chain n-3 Fatty Acids Supplementation During Caloric Restriction on Body Composition in Overweight and Obese Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

This systematic review aimed to determine whether caloric restriction-induced reduction in body fat and fat-free mass can be amended by supplementation with long-chain n-3 polyunsaturated fatty acids. Databases, including PubMed, Google Scholar, Web of Science, and EMBASE, were searched for papers published from the time the databases were created until November 1, 2023. Random-effects model meta-analyses were conducted using Review Manager 5.4.1 software. Statistical heterogeneity was assessed using the I². A standardized mean difference with a 95% confidence interval was calculated, and pooled effects were assessed. The initial search identified 1527 articles and 11 studies met the review inclusion criteria with 637 participants included. The participants' ages ranged between 18 and 61 years with a mean body mass index ranging between 27 and 36 kg/m². The changes in fat-free mass (standardized mean difference = 0.12, 95% CI −0.14 to 0.37, p = 0.36; I²:35%) and fat mass (standardized mean difference = − 0.01; 95% CI −0.25 to 0.24; p = 0.96; I²: 46%) were not different between intervention and control groups. The current review indicates that long-chain n-3 polyunsaturated fatty acids supplementation during caloric restriction neither attenuates the decline in fat-free mass nor enhances the reduction in fat mass. Considering the small number of studies and interventions included, further research is needed to investigate the effectiveness of long-chain n-3 polyunsaturated fatty acids supplementation during caloric restriction.