Getting more sleep might reduce your child’s risk of obesity.

Through the fog of sleep, I hear my favorite early-morning disk jockey tout a nutritional supplement that helps her lose weight while she sleeps.

“I just take three capsules before bed,” she says, “and that’s all it takes to curb my appetite all day.”

Before hitting the snooze button, I think, “I’ve got to get some of that stuff.”

Then I wake up for real and know this promise sounds way too good to be true.

As it turns out, science has shown that sleep actually does play a role in maintaining a healthy weight. The trick is to get enough sleep.

As early as 2005, the journal Archives of Internal Medicine reported that adults who sleep less tend to have a higher body mass index. Last year, another study from Northwestern University found that children who slept an hour less per night over five years were more likely to have a higher body mass index and be overweight.

The researchers also noted that the times children went to bed and woke up had an effect on weight for different age groups. It appears that a later bedtime had a greater effect on whether children ages 3 to 8 became overweight; an earlier wake time played a greater role for children ages 8 to 13.

Researchers at the University of Michigan recently found that children who were short-changing sleep in third grade had 40 percent higher odds of being obese in sixth grade, and sixth-graders who weren’t getting enough sleep were 20 percent more likely to be obese, compared to their well-rested peers.

The study’s lead author, Dr. Julie Lumeng, an assistant research scientist at the University of Michigan Center for Human Growth and Development, said that even after compensating for other factors, such as the home environment, the link between less sleep and heavier weight was still apparent.

What’s The Connection?
Researchers don’t yet know exactly why sleep and childhood obesity may be related, but they have some ideas. First, if children don’t get enough sleep at night, they’ll be less likely to run around and get exercise during the day.

Second, when kids are tired, they’re more irritable and may reach for junk food to help regulate their mood. They also have more awake time in which to eat.

And, finally, there appears to be a possible connection between sleep and fat metabolism. Studies done with adults suggest that the same pathways and hormones that regulate sleep and wakefulness also affect appetite. In other words, sleep deprivation actually appears to increase hunger.

Today’s Kids Are Sleeping Less
Most of us recognize a growing epidemic of obesity among children. Less well-known is that American children of all ages are sleeping one to two hours less per night than they need, according to polls by the National Sleep Foundation.

The U-M study found a discouraging trend in how much—or little—sleep kids are getting, particularly on weeknights. By age 7, children in the study were sleeping, on average, less than 10 hours on weekdays. This dropped to 8.5 hours by age 14. Sixteen percent of adolescents aged 13 to 18 slept less than seven hours on weeknights.

While there’s no magical number of hours required by all kids, most children’s sleep requirements fall within a predictable range based on their age.

The National Sleep Foundation recommends that 5- to 12-year-olds get 10 to 11 hours of sleep nightly and that teens get eight to nine hours.

What’s more, it appears the weight-sleep connection works in reverse, also. The risk of sleep apnea in obese children is four to five times that of normal-weight children. Obstructive sleep apnea is a breathing disorder that occurs during sleep and affects about 1 to 3 percent of children in the United States.

The resulting sleeplessness often leads to problems with attention, behavior and academics—and increased risk for obesity. Sound like a vicious cycle?

What’s A Parent To Do?
First of all, don’t wait to fully understand what links sleep and obesity before taking action. Make healthy sleep patterns a priority for the whole family.

If your child is overweight, look for signs of obstructive sleep apnea, and let your pediatrician know if you see any of them. Keep track of when and under what circumstances your child is most likely to overeat and note if these are times when he seems sleepy or tired.

If researchers are right, the risk of being obese decreases with each additional hour that your child sleeps! This may well be the single greatest argument parents will ever have in getting our teenage daughters to go to bed at a reasonable hour.

And once our kids go to bed earlier, we can get more sleep ourselves. Maybe then all that dieting will start to pay off.

Sidebar: Sleep Deprivation Adds Up
Lack of sleep affects more than just a child’s weight. Short sleep has been associated with poor educational performance, alcohol use and addiction, poor immune responses, hypertension, diabetes, and cardiovascular disease.

And sleep deprivation adds up over time, so an hour less per night is like a full night without sleep by the end of the week. Among other things, sleep deprivation can lead to:

• decreased attentiveness
• decreased short-term memory
• inconsistent performance
• delayed response time

These can cause generally bad tempers, problems in school, stimulant use, and driving accidents (more than half of “asleep-at-the-wheel” car accidents are caused by teens).