Preschool children who are in bed by 8 p.m. are far less likely to be obese during adolescence than children who stay up late, a study has found. Their risk of teenage obesity is half the risk faced by preschoolers who stay up past 9 p.m.
The research analyzed data gathered on nearly 1,000 children born in 1991 whose bedtimes were recorded when they were 4½ years old, and whose height and weight were recorded at age 15. The children were part of the Study of Early Child Care and Youth Development, done under the auspices of the National Institute of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development.
Among the children who were in bed by 8 p.m., 10 percent were obese as teens, compared to 16 percent of those who went to bed between 8 and 9 and 23 percent of those who went to bed after 9, according to the study, published in The Journal of Pediatrics.
The researchers adjusted for such factors as socioeconomic status, maternal obesity and parenting style and still found that the children who went to bed by 8 p.m. were at less than half the risk of teenage obesity as those who were up past 9, said Sarah E. Anderson, the paper’s lead author and an associate professor of epidemiology at the Ohio State University College of Public Health in Columbus.
Although the study does not prove that early bedtimes protect against obesity, Dr. Anderson said, “there is a great deal of evidence linking poor sleep, and particularly short sleep duration, to obesity, and it’s possible the timing of sleep may be important, above and beyond the duration of sleep.”
“This provides more evidence that having an early regular bedtime and bedtime routine for young children is helpful,” she said.