A population-based cohort study examined the relationship between sleep duration and nighttime energy intake in young children. The study involved 1278 families from the Gemini twin cohort, with data collected from children aged 16 and 21 months. Shorter sleep duration in young children was associated with higher nighttime energy intake, particularly from milk drinks. Children who slept less than 10 hours per night consumed on average 120 more calories at night than those who slept 13 hours or more. The majority of nighttime energy intake came from milk drinks, and these associations remained significant even after adjusting for various factors including age, sex, birth weight, and daytime sleep. The study found that shorter sleepers had later bedtimes and earlier wake times, which may contribute to increased nighttime energy intake. The findings suggest that providing milk drinks at night may contribute to excess energy intake in young children, highlighting the need for interventions targeting nighttime drinking habits. The study also indicates that nighttime energy intake may be a mechanism through which sleep influences weight gain in early childhood. However, further research is needed to confirm the long-term effects of these patterns on weight development. The study underscores the importance of understanding the relationship between sleep and energy intake in young children to develop effective strategies for preventing childhood obesity.A population-based cohort study examined the relationship between sleep duration and nighttime energy intake in young children. The study involved 1278 families from the Gemini twin cohort, with data collected from children aged 16 and 21 months. Shorter sleep duration in young children was associated with higher nighttime energy intake, particularly from milk drinks. Children who slept less than 10 hours per night consumed on average 120 more calories at night than those who slept 13 hours or more. The majority of nighttime energy intake came from milk drinks, and these associations remained significant even after adjusting for various factors including age, sex, birth weight, and daytime sleep. The study found that shorter sleepers had later bedtimes and earlier wake times, which may contribute to increased nighttime energy intake. The findings suggest that providing milk drinks at night may contribute to excess energy intake in young children, highlighting the need for interventions targeting nighttime drinking habits. The study also indicates that nighttime energy intake may be a mechanism through which sleep influences weight gain in early childhood. However, further research is needed to confirm the long-term effects of these patterns on weight development. The study underscores the importance of understanding the relationship between sleep and energy intake in young children to develop effective strategies for preventing childhood obesity.