Associations between sleep duration and dietary quality: Results from a nationally-representative survey of US adults

Insufficient sleep duration is a recognized determinant of cardiometabolic disease, with poor diet quality as a likely intermediate. Yet, inconsistencies in findings on sleep duration and diet quality among adult populations remain, particularly regarding a potential non-linear relationship. Thus, within a nationally representative survey of US adults (2011-2016 National Health and Nutrition Survey), we evaluated cross-sectional associations between sleep duration and diet quality. Self-reported typical sleep duration was categorized into four groups (≤5 h per night, 6 h, 7-8 h, and ≥9 h per night). Diet was assessed with two 24-h recalls (averaged), and diet quality was measured with the Healthy Eating Index-2015 (score range 0-100), which is comprised of 13 dietary components. Regression analyses that accounted for complex survey weights were used to compute multivariable-adjusted models of sleep duration categories and HEI-2015 overall scores, and individual HEI components. Within this nationally-representative sample of adults ≥18 years, 10% reported 5 or fewer hours of sleep, and 20% reported 6 h, while 12% obtained ≥9 h (long sleep duration). Compared to adults with 7-8 h of sleep, those with ≤5 h had 1.7 lower multivariable-adjusted HEI-2015 score (95% CI 0.6, 2.7), and those with ≥9 h had 1.2 lower adjusted HEI-2015 score (95% CI 0.2, 2.2). Upon examination of individual HEI-2015 components, short sleepers had lower consumption of healthier components (total fruits, whole fruits, total vegetables, greens and bean, whole grains, dairy, total protein, and seafood), while long sleepers had higher consumption of some unhealthier components (refined grains and added sugar) as well as some healthier components (dairy and total protein). In conclusion, within a nationally-representative US survey, a reverse U-shaped association was observed between sleep duration and dietary quality.