Early bedtimes for children could reduce risk of obesity later in life

According to the study by researchers from The Ohio State University College of Public Health, putting preschoolers to bed later in the evening, especially after 9 p.m., increases their risk of becoming obese.

To assess the effect of varying bedtimes, the team looked at data from 977 preschoolers who were part of the Study of Early Child Care and Youth Development, a project that followed healthy babies born at 10 different US sites in 1991.

Bedtimes for the children, who were aged around 4 ½, were split into three categories. Around a quarter of the children went to bed at 8 p.m. or earlier, around half between 8 p.m. and 9 p.m., and the remaining quarter after 9 p.m.

The researchers then linked the children's bedtimes as preschoolers to the levels of obesity in the children ten years later when the average age of the children was 15.

The results showed that of the children who went to bed before 8 p.m., only 10 percent were obese as teenagers.

However this number increased to 16 percent for those that had gone to bed between 8 p.m. and 9 p.m., and more than doubled to 23 percent for those who had gone to bed the latest, after 9 p.m.

The study, which is the first to use data on obesity collected around a decade after the childen were in preschool, also supports the existing research on the impact of sleep on obesity.

Previous studies have also shown that the majority of young children are biologically pre­programmed to be ready to fall asleep well before 9 p.m., with lead author Sarah Anderson commenting that, although putting children to bed earlier doesn't guarantee that they will immediately fall asleep, it does make it more likely that they will get the amount of sleep they need.