1019 Autism Spectrum Mealtime Behavior: Links to Tryptophan Index and Sleep Patterns in Children Aged 3–6 Years

Abstract Introduction Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by two main domains: (1) social communication and interaction, and (2) restricted, repetitive patterns of behavior, interests, or activities. Parents and caregivers of children with ASD have reported problematic mealtime behaviors; however, it is unclear which of these behaviors impact sleep. Additionally, a higher intake of tryptophan at breakfast may promote serotonin synthesis in children. This study aimed to investigate the association between mealtime behaviors and sleep behaviors in children aged 3-6 years. Methods A total of 283 children aged 3-6 years were included in the study. Mealtime behaviors were assessed using the Autism Spectrum Disorder Mealtime Behavior Questionnaire (ASD-MBQ), focusing on selective eating, clumsiness/manners, interest and concentration on eating, oral motor function, and overeating. Data on wake-up time, bedtime, total sleep duration, and midpoint of sleep were collected. The Tryptophan index (Trp-index) at breakfast was calculated as the amount of tryptophan per meal, based on the tryptophan content per 100 g of food and a standard portion size per meal. Results Compared to the non-selective eating group (n=121), the selective eating 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 duration (9.5 ± 0.6 vs. 9.3 ± 0.7 hours; P = 0.021), and a lower Trp-Index (285 ± 167 vs. 234 ± 149; P = 0.007). However, there were no significant differences between the groups in age, sex, or breakfast frequency per week. Additionally, three other mealtime behaviors—interest and concentration on eating, oral motor function, and overeating—did not appear to influence sleep behavior. Conclusion We identified mealtime behaviors associated with sleep patterns and tryptophan intake at breakfast. This information can help healthcare professionals educate families about problematic mealtime and sleep behaviors in preschool children. Support (if any) This work was supported by JSPS KAKENHI Grant Number 22K02429, 23K17594, 23K02305, and 24K13998.