Why is an epidemic of childhood and adolescent obesity sweeping the United States? There is no single answer to that question, but if you are thinking fast food and video games are solely to blame, think again. At least part of the answer may lie in the simple process of sleep. Our kids are getting too little of it.
Consider these older research findings:
Now a new study has added additional insights to what's emerging as an impressive body of evidence. In the September issue of Archives of Pediatric and Adolescent Medicine (a JAMA/Archives journal), Janice Bell of the University of Washington and Frederick Zimmerman of the University of California, Los Angeles, report on long-term studies (since 1997) of weight and sleep patterns in nearly 2,000 children. No surprise: they found that 33 percent of the younger children and 36 percent of the older ones were overweight or obese.
But when it came to sleep, the researchers did uncover a few surprises. Specifically, they found that overweight and obesity are associated with nighttime sleep duration (not napping) in two significant ways:
Although historical records show that we've grown heavier as our hours of sleep have decreased, experts caution that they can't be sure about the cause-and-effect relationship. Are we overweight because we sleep less, or do we sleep less because we are overweight? Or is some other factor, such as stress or the electric light, promoting both overweight and sleep loss? Until these questions are answered, it makes sense to include a good night's sleep in any plan for weight control--and to establish and enforce a bedtime for children and teens. "Sleep duration is a modifiable risk factor with potentially important implications for obesity prevention and treatment," say Bell and Zimmerman.
What's the best way to modify that risk factor? Put your kids to bed.
How much sleep do children and teens actually need? On average, (your child may need more):
o Toddlers (ages 18 months to 3 years): 12-14 hours in a 24-hour period
o Preschoolers (ages 3-5): 11-13 hours per night
o School children (ages 5 to 12): 10-11 hours per night
o Teens (13-17): 9 or more hours per night
For More Information:
Newest study: Janice F. Bell and Frederick J. Zimmerman. "Shortened Nighttime Sleep Duration in Early Life and Subsequent Childhood Obesity," Arch Pediatr Adolesc Med. 2010;164(9):840-845.
For additional information on sleep, visit the website of the National Sleep Foundation.
Please leave a comment if you would like a list of the older studies cited in this blog.