Not getting enough shuteye can make kids wake up on the wrong side of the bed, with a day that's long on moodiness and short on cooperation and attention. But a new study shows that skimping on ZZZs can affect kids' health in an even more serious way — making it more likely they'll become overweight.

Researchers set out to see if there was a link between sleep — or lack thereof — and putting on too many pounds. So, they looked at 800 kids' sleep patterns — problems and how long they snoozed — as well as their body mass index (BMI, a calculation using height and weight to estimate a person's body fat) over time.

What they found:

• Third-graders who didn't get the recommended amount of nightly sleep, regardless of their BMI, were more likely to be overweight in sixth grade. Indeed, every added hour of sleep in third grade meant a 40% drop in kids' risk of excessive weight gain by sixth grade.
• Sixth-graders who got less than the recommended 9 hours of nightly sleep were more apt to become overweight during that same school year. For every added hour of sleep they got, sixth-graders had a 20% less chance of becoming overweight.

What This Means to You

On top of putting kids at risk for becoming overweight, lack of sleep can lead to irritability, hyperactivity, and extremes in behavior. Plus, too-little sleep can make a condition like attention deficit hyperactivity disorder (ADHD) even worse. All of that added behavioral baggage can set the stage for problems in school and tension at home.

Kids need different amounts of sleep as they grow to help both their brains and their bodies function at their best. For 6- to 9-year-olds, it's about 10 hours a night, whereas for 10- to 12-year-olds quickly approaching their teens, it's slightly less (a little more than 9 hours a night). Of course, you're the best judge of how much rest your child needs each day — some kids may need a little more than others.

To help make healthy amounts of shuteye a regular occurrence in your household:

• Encourage your kids to go to bed at the same time every night and wake up at the same time every morning, allowing for the right amount of time they need for their age and personal stage.
• Carve out some private time with each child — without siblings — just before bedtime to talk about the day, read together, or listen to soothing music. This can make the nightly routine feel a little more special and personal.
• Encourage regular physical activity, but not within 2 to 3 hours of bedtime.
• Limit caffeine-containing beverages, especially after 4 PM.
• Keep bedrooms room cool, dark, and noise-free. Consider eliminating distractions by putting TVs, video consoles, and computers in a common area of your home instead of a child's room, where kids may be perpetually tempted to watch or play for "just one more minute."

Reviewed by: Steven Dowshen, MD
Date reviewed: November 2007

Source: "Shorter Sleep Duration Is Associated With Increased Risk for Being Overweight at Ages 9 to 12 Years," Pediatrics, November 2007.