Clinical Outcomes of Dietary Replacement of Saturated Fatty Acids with Unsaturated Fat Sources in Adults with Overweight and Obesity: A Systematic Review and Meta-Analysis of Randomized Control Trials.

BACKGROUND: Obesity and dyslipidemia are frequently treated with dietary interventions before pharmacotherapy is given. Diets high in unsaturated fat have proven advantageous to disease treatment.

AIMS: The purpose of this systematic review and meta-analysis was to assess the evidence of the effect of saturated fatty acids (SFA) replacement with unsaturated fatty acids (UFA) in metabolically healthy adults with overweight and obesity on markers of dyslipidemia and body composition.

METHODS: Keyword search was performed in PubMed, CINAHL, and Cochrane Library for randomized controlled trials (RCTs) evaluating the effects of fatty acid substitution in adults with overweight and obesity. Meta-analysis was performed on interventions assessing lipoprotein levels and body composition. Publication bias was assessed by funnel plot inspection, Begg's, and Egger's test.

RESULTS: Eight RCTs enrolling 663 participants were included in the review, with intervention durations between 4 and 28 weeks. Although nonsignificant (p = 0.06), meta-analysis found UFA replacement to reduce total cholesterol concentrations by 10.68 mg/dL (95%CI -21.90 to 0.53). Reductions in low-density lipoprotein cholesterol and triglycerides were statistically nonsignificant.

CONCLUSIONS: Due to null results and a small number of studies included, there is no strong evidence that replacement of SFA with UFA may benefit lipid profiles in this population.