Does your child sleep enough? Here are two little-known facts: Kids haven't been getting the expert-recommended amount of shut-eye for 100 years. And scientists don't know exactly how much sleep children really need.
A new study published in the journal Pediatrics looked back over sleep advice for children from 1897 to 2009, and found 32 different sets of official recommendations in that period. The researchers also looked at how much kids actually slept, and found that they consistently got an average of 37 minutes less than the recommended amount.
But almost none of the sleep advice was based on research. "After 100 years, we still don't have meaningful evidence for these recommendations," Lisa Anne Matricciani of the University of South Australia, lead author of the study, told the Wall Street Journal.
Here's more from the Los Angeles Times:
[T]he researchers could find only one case for which the expert guidelines were rooted in medical evidence of a need for a particular amount of sleep. That was a 1926 study that measured the actual sleep of 500 kids between the ages of 6 and 15 who were deemed "healthy." Other than that, it seems that experts simply looked at the amount of sleep children around them were getting and figured that they really needed a little bit more, the authors wrote.
The current advice from the National Sleep Foundation is that children ages 5 to 12 need 10 to 11 hours of sleep a night, and teenagers need 9 to 10 hours. But a 2006 sleep survey found that about 45 percent of kids ages 11 to 17 get less than eight hours of sleep a night. Any parent who has dealt with a cranky, sleep-deprived child knows that's not nearly enough.
Research also shows that it's unwise to let kids skimp: Lack of sleep for children is linked to problems such as obesity, learning difficulties, and aggressive behavior.
Image: Sleepy boy in classroom via Shutterstock.