Diet Quality Scores are Associated with Sleep Timing and Regularity in Emerging Adults

Background: Sleep health is associated with cardiometabolic health, potentially due to direct physiological effects, altered diet quality, or a combination of both. However, data on multidimensional sleep health, particularly sleep regularity and holistic dietary patterns, in emerging adults remain limited. Objective: To examine associations between sleep health and diet quality in emerging adults. Methods: Objective sleep (duration, efficiency, timing [bedtime, waketime, midpoint], regularity) was measured via actigraphy: n=106 (48M/58F, age [median = 22, IQR = 2] years, BMI [24.2, 4] kg/m2). Subjective sleep quality was measured via Pittsburgh Sleep Quality Index: n=122 (58M/64F, age [22, 2], BMI [24.2, 5] kg/m2. We collected diet data via daily food and fluid diaries (≥3 days) to determine Dietary Approaches to Stop Hypertension (DASH; 0-9) and Healthy Eating Index (HEI; 0-100) scores. We used hierarchical regressions (model 1: bivariate analysis, model 2: sex, BMI, race) to examine associations between sleep health and diet quality. We compared diet quality between participants obtaining adequate and inadequate sleep for each sleep health metric using Mann-Whitney U tests. Results: Sleep midpoint and bedtime were independently associated with DASH (Bs ≥ -0.165, ps ≤ 0.001) and HEI (Bs ≥ -2.180, ps ≤ 0.001) after inclusion of covariates. Group comparisons indicated higher diet quality among participants with adequate sleep midpoint and waketime SD (p ≤ 0.040). Conclusions: Higher sleep regularity is associated with better diet quality in emerging adults. These relations may be bidirectional, thus future studies are needed to investigate whether sleep health interventions improve diet quality, or vice versa, among emerging adults.