Association of Diet Quality, Dietary Acid Load, and Dietary Antioxidant Index With Cardiometabolic and NAFLD Risk Factors Among Patients With Metabolic Syndrome: A Cross-Sectional Study.

Metabolic syndrome (MetS) is closely associated with non-alcoholic fatty liver disease (NAFLD). Diet quality, acid-base balance, and antioxidant intake may influence NAFLD risk. This study examines the relationship between the Diet Quality Index (AHEI), Dietary Acid Load (DAL), and Dietary Antioxidant Index (DAI) with liver enzyme levels, lipid profiles, and NAFLD predictors in individuals with MetS. A cross-sectional study was conducted on 420 adults diagnosed with MetS according to International Diabetes Federation criteria in Zanjan, Iran. Dietary intake was assessed using a validated food frequency questionnaire. AHEI, DAL, and DAI were calculated. Liver enzymes, lipid profiles, and predictive indices, including the Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI), and Triglyceride-Glucose (TyG) Index, were analyzed. Multivariable regression adjusted for confounders. Higher AHEI (tertile 3 vs. tertile 1) was associated with lower FLI (65.37 ± 10.46 vs. 74.37 ± 11.39 (all values presented as mean ± standard deviation [SD]); p < 0.001), HSI (40.49 ± 6.17 vs. 47.28 ± 7.19; p = 0.02), triglycerides (163.40 ± 62.19 mg/dL vs. 174.43 ± 63.72 mg/dL; p = 0.034), ALT (22.67 ± 6.29 IU/L vs. 29.39 ± 7.43 IU/L; p = 0.023), and GGT (20.37 ± 7.12 IU/L vs. 27.91 ± 8.43 IU/L; p = 0.033), and higher HDL cholesterol (49.23 ± 15.93 mg/dL vs. 43.24 ± 13.39 mg/dL; p = 0.042). Higher DAL (tertile 3 vs. tertile 1) was linked to elevated FLI (79.43 ± 12.13 vs. 69.33 ± 10.36; p < 0.001) and ALT (30.75 ± 8.23 IU/L vs. 19.76 ± 5.43 IU/L; p = 0.002). Higher DAI (tertile 3 vs. tertile 1) was inversely associated with HSI (41.8 ± 5.1 vs. 46.5 ± 6.7; p = 0.005). Higher AHEI and DAI scores were associated with better liver function and lipid profiles, while higher DAL correlated with worse outcomes. Improving diet quality and balancing acid-base intake may be associated with reduced NAFLD risk in MetS patients.