Effect of Genetics-Based Personalized Nutrition and Lifestyle Advice vs Conventional Advice on Anthropometric Outcomes: A Systematic Review and Meta-Analysis.

CONTEXT: Many studies have focused on the concept of "nutrigenetics," which explores phenotypic responses to nutrition and lifestyle interventions in relation to an individual's genotype. No meta-analysis, to our knowledge, has evaluated their overall effects on health outcomes. OBJECTIVE: To systematically review and meta-analyze available clinical trials comparing the effect of genetically based personalized diet and lifestyle advice vs conventional diet and lifestyle advice on some anthropometric parameters. DATA SOURCES: Electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar, were systematically searched from inception to March 2026 to identify relevant articles. DATA EXTRACTION: Using a data extraction sheet, 1 author extracted the data, and another researcher checked them. For the meta-analysis, quantitative data, including the sample sizes of each group and the means and SD, or their equivalents, for study outcomes, were extracted. DATA ANALYSIS: Effect sizes were calculated as weighted mean differences (WMDs) and corresponding 95% CIs, and analyses were conducted using the random-effects method. A total of 6175 records were identified, of which 8 were included in the meta-analysis. This meta-analysis showed that the body weight and body mass index (BMI) of participants receiving personalized lifestyle advice decreased by 0.52 kg (95% CI, -1.04 to -0.003; P = .049) and 0.30 kg m-2 (95% CI, -0.43 to -0.16; P < .001), respectively, compared with controls. Body fat percentage did not change significantly. CONCLUSION: Overall, genetically based personalized nutrition and lifestyle advice may lead to a small but significant improvement in body weight and BMI compared with conventional advice, with no significant differences in body fat percentage. Therefore, more well-designed clinical trials are needed to confirm the effectiveness of genetically based personalized nutrition and lifestyle advice in weight management. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42024609177).