Northwestern University study indicates that getting inadequate sleep has negative effects on children’s social and emotional well-being and school performance and also increases their risk of being overweight.
The study — conducted in two waves of data collection approximately five years apart — is the first nationally representative, longitudinal investigation of the relationship between sleep, Body Mass Index (BMI) and overweight status in children aged 3 to 18.
“Our study suggests that earlier bedtimes, later wake times and later school start times could be an important and relatively low-cost strategy to help reduce childhood weight problems,” says Emily Snell. Snell is co-author of “Sleep and the Body Mass Index and Overweight Status of Children and Adolescents” in Child Development.
“We found even an hour of sleep makes a big difference in weight status,” said Snell, a Northwestern doctoral student in human development and social policy. “Sleeping an additional hour reduced young children’s chance of being overweight from 36 percent to 30 percent, while it reduced older children’s risk from 34 percent to 30 percent.”
The Northwestern study not only differs from most other investigations of the effects of sleep on children’s weight in its five-year approach. It also helps disentangle the issue of whether sleep actually affects weight or whether children who already are overweight are simply poor sleepers. In addition, it takes into account the possible effects of other variables including race, ethnicity and income.