Researchers have shown healthy sleep for children is not just about getting 10 hours a night, revealing a link between late bedtimes and unhealthy weight gain.

A University of Queensland and James Cook University study highlights the importance of parents looking beyond sleep duration and into the benefits of a consistent early bedtime.

The team analysed four years of data from 1250 Aboriginal and Torres Strait Islander children involved in the Longitudinal Study of Indigenous Children (LSIC), and focused on children aged five to eight years.

Dr Yaqoot Fatima from UQ’s Institute for Social Science Research said children with consistent late bedtimes were at increased risk of being overweight or obese compared to children who regularly went to bed earlier.

“Our study, which is applicable to non-Indigenous children as well, looked at about 7pm as an early bedtime, and after 9.30pm on weekdays and weekends as being late,” Dr Fatima said.

"Compared with early sleepers, children we might describe as ‘night owls’ were on average 1.5kg to 2.5kg heavier at follow up three years later."

Dr Fatima said researchers had often focused on sleep duration as a risk factor, but the study showed other dimensions, such as timing, were important.

“Excessively focusing on sleep duration as the sole measure of healthy sleep would not be sufficient to achieve better health outcomes in children,” she said.

The researchers said small numbers in the early sleeping group is a limitation. Nonetheless given that the results were robust to adjustment for key determinants of obesity e.g., food habits, they would now work with Indigenous communities, to discuss the findings and seek input in developing sleep health recommendations for children.

“About 30 per cent of study population lived in remote and very remote areas and their average disadvantage and geographical remoteness increased their risk of poor sleep,” Dr Fatima said.

“It is important to share the information on the role of sleep timing with parents, carers and health service provides so that more can children benefit from regular and consistent bedtimes and healthy sleep.”

UQ Associate Professor Abdullah Mamun co-authored the study along with colleagues from La Trobe University and the University of Western Australia.

The research is published in Acta Paediatrica.

The researchers gratefully acknowledged the children and families in the LSIC study, and thanked the Australian Government Department of Social Services for providing access to the data.

Contact: Dr Yaqoot Fatima, ph +61 (0)457 024 222, fatima.yaqoot@uq.edu.au.