Association between sleep timing and meal and snack patterns in schoolchildren in southern Brazil

This study aimed to identify meal and snack patterns and assess their association with sleep timing in schoolchildren. This is a cross-sectional study carried out in 2018/2019 with 1333 schoolchildren aged 7-14 years from public and private schools in Florianópolis, Brazil. Previous-day dietary intake data for breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner and evening snack were collected using a validated online questionnaire. Sleep timing was measured by the midpoint of sleep and classified as quartiles (very early, early, late and very late). Latent class analysis was performed to identify meal and snack patterns, and multinomial logistic regression was used to assess associations. Students with very late sleep timing were less likely to consume the 'coffee with milk, bread and cheese' breakfast pattern compared with very early group. Also, the former were more likely to consume the 'mixed' breakfast pattern (healthy and unhealthy foods) compared with very early students. The latter were more likely to eat the 'Brazilian traditional, processed meat, egg and fish' lunch pattern to the late students and less likely to consume the 'pasta and cheese' lunch pattern compared with the students with later sleep timing. Students with later sleep timing were more likely to eat ultra-processed food at mid-afternoon snacks compared with early group. The study findings suggest that morning preference appears to promote healthier breakfast, lunch and afternoon snack patterns, whereas later sleep timing may pose challenges in maintaining healthy patterns at these meals/snacks.