P023 Dinner timing and post-dinner-to-bedtime window in relation to sleep

Abstract

Background

Meal timing may act as a circadian cue, influencing internal biological rhythms and sleep patterns. This study examined how these patterns relate to subjective sleep outcomes in different chronotypes.

Methods

Participants (n = 132) completed the Pittsburgh Sleep Quality Index (PSQI), Munich Chronotype Questionnaire (MCTQ), and a meal timing survey online. Based on median splits, dinner timing was categorised as early (<19:00) or late (≥19:00), and post-dinner-to-bedtime window as short (<3.51 h) or long (≥3.51 h). Mann–Whitney U tests and linear regression models (adjusted for age, sex, chronotype, and lifestyle factors) were used to assess associations.

Results

Of 132 participants, 4 individuals reported usually not consuming dinner. There was a significant difference between early and late chronotype (n = 128) regarding dinner time (1h later in late chronotype) and the post-dinner-to-bedtime window (~4h in late chronotype compared to 3.5h in the early type) (p=.001). Shorter post-dinner-to-bedtime window was linked to longer weekday sleep duration (p=.005), lengthier time in bed (p=.001 weekday, p=.042 free day), and higher sleep efficiency (p=.002). These associations remained significant after statistical adjustment. No significant associations were observed for PSQI, social jetlag, or sleep loss.

Discussion

Evening meal timing may influence sleep and contribute to circadian alignment. These findings suggest that avoiding late dinners and reducing the interval before bedtime or shifting to an earlier sleep schedule could serve as a practical, non-invasive strategy to enhance sleep duration and efficiency, highlighting meal timing as a potential addition to sleep hygiene guidelines.