Introduction:
The Healthy Eating Index (HEI)-2015 quantifies alignment with the 2015-2020 Dietary Guidelines for Americans by scoring and totaling 13 components. Higher scores have been associated with lower all-cause and cardiovascular disease (CVD) mortality. The contributions of individual components toward total diet quality and associations with health in American adults have not been determined.
Hypothesis:
It was hypothesized that the individual HEI-2015 components would differentially contribute to total diet quality and correlate with CVD risk factors in U.S. adults.
Methods:
Non-pregnant, non-lactating adult participants (age 19+ years) in the National Health and Nutrition Examination Survey (NHANES) 2001-2016 with at least one reliable 24-hour dietary recall were included in the analysis (n=39,799). Total and component HEI-2015 scores were calculated per person using a single recall. Linear regression models accounting for the complex sampling design were used to assess associations between total and component HEI-2015 scores and CVD risk factors after adjustment for potential confounders. Significance of beta coefficients was defined by p<0.01.
Results:
Total HEI-2015 score was positively associated with high-density lipoprotein cholesterol (HDL-C; ß±SE, 0.10±0.01 mg/dL) and inversely associated with BMI (-0.05±0 kg/m
2
), waist circumference (WC; -0.13±0.01 cm), systolic blood pressure (SBP; -0.04±0.01 mmHg), low-density lipoprotein cholesterol (LDL-C; -0.09±0.03 mg/dL), triglycerides (-0.20±0.08 mg/dL), fasting glucose (-0.05±0.02 mg/dL), and insulin (-0.03±0.01 μU/mL). All component scores increased with total score. The Whole Grains and Fatty Acid Ratio components made the greatest contributions (both +0.12 points or 12%) to each one-unit increase in HEI-2015, followed by moderation components Refined Grains and Saturated Fat (both +0.11 or 11%). Increases in the Fatty Acid Ratio score were explained by decreasing saturated fat (-1.67 g/unit, 95% CI: -1.73 to -1.61) and increasing polyunsaturated fat (PUFA; 1.17 g/unit, 95% CI: 1.12, 1.22); increases in monounsaturated fats were relatively small (0.18 g/unit, 95% CI: 0.11 to 0.25). The predominant PUFA was linoleic acid, which increased 1.06 g/unit (95% CI: 1.02 to 1.11). Scores for grain-related components were favorably associated with BMI, WC, SBP and HDL-C; fat quality components were inversely associated with BMI, WC, HDL-C, LDL-C, and triglycerides.
Conclusion:
Diet quality is favorably associated with several CVD risk factors. Approximately 50% of each 1-point increase in HEI-2015 is related to the quality of grain-based products and fat sources. Choosing whole grains instead of refined grains, and PUFA in place of saturated fats, is associated with improvements in diet quality and cardiovascular health.
The associations between whole grain and refined grain intakes and serum C-reactive protein
