Diet Quality and Mortality Risk in Metabolically Obese Normal-Weight Adults

Objective To examine the associations among the Dietary Approaches to Stop Hypertension (DASH)–style diet, the Healthy Eating Index (HEI), and mortality risk in metabolically obese normal-weight (MONW) adults. Patients and Methods Data were from normal-weight (body mass index of 18.5 to <25) adults aged 30 to 90 years at baseline in the Third National Health and Nutrition Examination Survey, October 18, 1988, through October 15, 1994, followed up for deaths (all-cause, cardiovascular, and cancer related) until December 31, 2011. A total of 2103 participants without known cardiovascular disease and cancer at baseline were included in this prospective cohort study. Metabolic obesity was defined as having 2 or more of the following: high glucose, blood pressure, triglyceride, C-reactive protein, and insulin resistance values and low high-density lipoprotein cholesterol levels; metabolic healthy status was defined as having 0 or 1 of these metabolic derangements. Results During median follow-up of 18.6 years, there were 344 and 296 deaths in the MONW and metabolically healthy normal-weight (MHNW) phenotypes, respectively. In MONW individuals, a 1-SD increment in adherence to a DASH diet (2 points) or HEI (14 points) was significantly associated with reductions (17% [hazard ratio (HR), 0.83; 95% CI, 0.72-0.97] and 22% [HR, 0.78; 95% CI, 0.68-0.90], respectively) in the risk of all-cause mortality, after adjustment for potential confounders. The corresponding HRs for cardiovascular disease mortality were 0.72 (95% CI, 0.55-0.94) and 0.79 (95% CI, 0.65-0.97), respectively. In addition, reduction of cancer mortality was observed with 1-SD increment of HEI (HR, 0.63; 95% CI, 0.46-0.88). However, no association was observed in the MHNW phenotype. Sensitivity analyses suggested relationships robust to different definitions of MONW and also dose responses with the number of metabolic derangements. Conclusion Higher diet quality scores were associated with lower risk of mortality in normal-weight individuals with metabolic abnormalities.