Benjamin Franklin may have been on to something when he prescribed "early to bed" for better health.
This could be especially true in the ongoing fight against childhood obesity. A recent study found that preschoolers who went to bed after 8 p.m. had a significantly higher risk of becoming obese teenagers than those with earlier bedtimes.
Led by researchers at Ohio State University, the study, published in the Journal of Pediatrics, followed 977 children from ages 4.5 to 15 years, asking their parents what time they typically were put to bed on the weekdays. Bedtimes ranged from 6:45 p.m. to 1:30 a.m., with the most common times being 8 p.m., 8:30 p.m., and 9 p.m.
The scientists also examined the children's height, weight and body mass index as teenagers.
"Pre-school-aged children with early weekday bedtimes were half as likely as those with late bedtimes to become obese as adolescents," the researchers wrote.
In fact, only 10 percent of the children who were put to bed by 8 p.m. were obese later, the study said. But 23 percent of the late-nighters (those who went to bed after 9 p.m.) became obese teenagers.
While it's unclear exactly how children's bedtimes affect body weight, other studies have found that a lack of sleep is linked to hormones that regulate appetite and metabolism. Staying up late also increases opportunities to snack after dinner.
As work and school schedules get busier, it's a bigger challenge to establish early bedtimes, the study noted.
"For young children, parents create the routines that allow children to obtain sufficient sleep to meet their physiologic needs. However, in establishing young children's bedtimes, like other household routines, parents must often make compromises as they face competing time demands," the authors wrote.
"For example, some parents' work schedules do not allow them to arrive home early enough in the evening to spend time with their child and also maintain an early bedtime. This may push children's bedtimes later.
"At the same time, early bedtimes are required for adequate night sleep if children must wake to accommodate their parents' work or siblings' school start times."
