This study investigates the relationship between sleep duration and nighttime energy intake in young children, aiming to test the hypothesis that shorter-sleeping children consume more calories at night. The study used data from 1278 families participating in the Gemini twin cohort, with one child per family selected randomly to avoid clustering effects. Nighttime sleep duration was measured at 16 months of age, and energy intake by time of day and eating episode (meal, snack, drink) was derived from 3-day diet diaries completed when children were 21 months old. Key findings include: - Shorter-sleeping children (less than 10 hours of sleep per night) consumed an average of 120 more calories at night compared to those sleeping 13 hours or more. - The majority of nighttime intake came from milk drinks. - Associations remained significant after adjusting for various confounders, including age, sex, birth weight, gestational age, maternal education, weight, and daytime sleep. The study concludes that shorter-sleeping young children consume more calories, predominantly at night, and from milk drinks. This finding suggests that providing milk drinks at night may contribute to excess intake and could be a target for intervention to address the association between sleep and weight gain observed in early childhood.This study investigates the relationship between sleep duration and nighttime energy intake in young children, aiming to test the hypothesis that shorter-sleeping children consume more calories at night. The study used data from 1278 families participating in the Gemini twin cohort, with one child per family selected randomly to avoid clustering effects. Nighttime sleep duration was measured at 16 months of age, and energy intake by time of day and eating episode (meal, snack, drink) was derived from 3-day diet diaries completed when children were 21 months old. Key findings include: - Shorter-sleeping children (less than 10 hours of sleep per night) consumed an average of 120 more calories at night compared to those sleeping 13 hours or more. - The majority of nighttime intake came from milk drinks. - Associations remained significant after adjusting for various confounders, including age, sex, birth weight, gestational age, maternal education, weight, and daytime sleep. The study concludes that shorter-sleeping young children consume more calories, predominantly at night, and from milk drinks. This finding suggests that providing milk drinks at night may contribute to excess intake and could be a target for intervention to address the association between sleep and weight gain observed in early childhood.