Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) style diet, and metabolic health in U.S. adults.

BACKGROUND & AIMS: There is sparse evidence on the relationship between the Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) style diet, and metabolic health, especially comparing cardiometabolic phenotypes among in normal weight and obese populations. We aimed to investigate the association of the Mediterranean diet scores (MDS) and DASH index with metabolically healthy obese (MHO) and metabolically obese normal weight (MONW) phenotypes in a representative U.S.

METHODS: MDS and DASH index were calculated using dietary data from 2767 adults aged 20-90 years without any prior diagnosis of cancer or cardiovascular disease from the National Health and Nutrition Examination Survey III, 1988-1994. MHO and MONW individuals were identified using fasting glucose, insulin resistance, blood pressure, triglycerides, C-reactive protein, and high-density lipoprotein-cholesterol.

RESULTS: Higher MDS was associated with higher odds of MHO phenotype (odds ratio (OR)T3 vs T1, 2.57 [95% confidence interval (CI), 1.04-6.35]; P trend = 0.04), and higher DASH index was associated with lower odds of MONW phenotype (ORT3 vs T1, 0.59 [95% CI, 0.38-0.93]; P trend = 0.03) only in the younger age group (<45 years for men or premenopausal women). No significant associations of MDS and DASH index with MHO and MONW phenotypes were observed in the older age group (≥45 years for men or postmenopausal women).

CONCLUSIONS: Adherence to Mediterranean diet or DASH style diet was favorably associated with MHO and MONW phenotypes only in the younger age group, suggesting that potential dietary intervention to prevent cardiometabolic disease differ by age group.