Selective Eating Behavior and Delayed Bedtime in Children Aged 3-6 Years: The Mediating Role of Breakfast Tryptophan...

Mealtime behaviors may influence sleep patterns in preschool children; however, this relationship remains unclear. This study aimed to clarify which mealtime behaviors affect sleep among preschool children. A total of 283 children aged 3-6 y were included in this study. Problematic mealtime behaviors-such as selective eating, clumsiness/manners, interest and concentration in eating, oral motor function, and overeating-were assessed. Data on wake-up time, bedtime, total sleep duration, and sleep midpoint were collected. The tryptophan index (Trp index) was calculated at breakfast. A mediation analysis, controlling for age in month and sex, was conducted under the assumption of a causal pathway from selective eating behavior to bedtime via the Trp index. The analysis estimated both direct and indirect effects. Compared to the non-selective eating behavior group (n=121), the selective eating behavior group (n=162) exhibited later wake-up times (6:44±0:28 vs. 6:52±0:32; p=0.043), later bedtimes (21:15±0:37 vs. 21:33±0:33; p<0.001), later midpoints of sleep (2:00±0:27 vs. 2:13±0:31; p<0.001), shorter total sleep (9.5±0.6 vs. 9.3±0.7 h; p=0.018), and a lower Trp-index (285±167 vs. 234±149; p=0.007). Selective eating behavior was associated with lower tryptophan intake at breakfast, which in turn was linked to later bedtimes. The mediation analysis showed that tryptophan intake partially mediated the relationship between selective eating behavior and sleep timing (proportion mediated=13.6%). These findings suggests that a significant association was observed between selective eating behavior and poor sleep habits, and tryptophan intake at breakfast partially mediated this association.