Chrononutrition and Diet Quality in Preschool Children: An Association Shaped by Chronotype.

BACKGROUND: Later timing of eating may be associated with lower diet quality, and chronotype may act as an effect modifier. OBJECTIVE: We examined the association between chrononutrition and diet quality and chronotype as a potential effect modifier in 656 Finnish 3-6-year-olds from the DAGIS Survey 2015-2016. METHODS: Eight chrononutrition variables were calculated using a 3-day food record and sleep data obtained from 7-day actigraphy. Diet quality was assessed using food frequency questionnaires to derive the Healthy Food Intake Index score. Chronotype was estimated as the midpoint of sleep corrected for sleep debt, categorizing earliest 10% as early, middle 80% as intermediate, and latest 10% as late chronotypes. Parental education level, age, and sex were accounted for as potential confounders. RESULTS: In the whole sample, linear regression models indicated that a longer morning latency (β = -0.34, [95% CI -0.65, -0.02]), later eating midpoint (-0.70, [-1.18, -0.22]), and last eating occasion (-0.45, [-0.80, -0.01]), were associated with lower diet quality. Chronotype stratified analyses revealed that longer evening latency was inversely associated with diet quality only in early chronotypes (-1.22, [-2.36, -0.08]). Conversely, later eating midpoint and last eating occasion were inversely associated with diet quality in intermediate (-0.70, [-1.20, -0.20]);-0.46, [-0.82, -0.09]) and late (-2.47, [-3.88, -1.06]; -1.29, [-2.43, -0.16]), but not in early chronotypes. CONCLUSIONS: The findings indicate that a longer morning latency, and later timings for eating midpoint and last eating occasion, are associated with lower diet quality, and chronotype acts as an effect modifier in some associations.