"We viewed how long parents slept and how long children slept as part of a household routine and found that they really did go together," study author Barbara Fiese, director of the Family Resiliency Center at the University of Illinois in Urbana, said in an university news release.
Researchers assessed the weight of 337 preschool children and their parents, as well as factors that could protect against overweight and obesity.
The protective factors assessed in parents included adequate sleep (more than seven hours a night) and family mealtime routine. The factors assessed in children included adequate sleep (10 or more hours a night), family mealtime routine, not having a television in the bedroom, and limiting screen time to less than two hours a day.
Getting adequate sleep was the only individual protective factor against overweight and obesity in children. Those who didn't get enough sleep were more likely to be overweight/obese than those who followed at least three of the other protective routines on a regular basis.
The researchers also found that the number of hours a parent sleeps per night affects their children's amount of sleep. This means that parents' sleep habits could affect their children's risk of being overweight/obese.
"Parents should make being well-rested a family value and a priority. Sleep routines in a family affect all the members of the household, not just children; we know that parents won't get a good night's sleep unless and until their preschool children are sleeping," Fiese said.
The study was published in a recent issue of the journal Frontiers in Psychology.
Although this study found an association between sleep and children's weight, it wasn't designed to prove that a lack of sleep by either parent or child is the cause of excess weight in children. However, Fiese noted that getting enough sleep may help regulate metabolism.
The U.S. Centers for Disease Control and Prevention offers tips for keeping children at a healthy weight.