Children who don't get enough sleep might be crankier than others, but they're also at increased risk of weight gain and type 2 diabetes, a new study published in the journal Pediatrics found.

Researchers from St. George’s, University of London, and the University of Glasgow looked at the weeknight sleeping patterns of nearly 5,000 nine- to 10-year-olds. The data collected suggest that sleep deprivation in children could be linked to the health issues.

The researchers found that for every extra hour of sleep the children got, risk factors for type 2 diabetes—such as body mass index (BMI), body fat, insulin resistance, and glucose levels—went down. On average, the children in the study slept 10.5 hours each night. 

Over the past 10 years, there has been growing evidence that children and adolescents are getting less and less sleep, says Christopher G. Owen, Ph.D., a study co-author and a professor of epidemiology at St. George’s, University of London.

At the same time, according to the National Institutes of Health, type 2 diabetes—a disease most commonly found in people over 45—is becoming more common in young people. According to a study published in JAMA, the prevalence of type 2 diabetes in 10- to 19-year-olds rose 30 percent between 2001 and 2009—and it has continued to rise.

Owen says the new results demonstrate that the increasingly widespread problems of sleep deprivation and type 2 diabetes in children may be linked.

What This Means for Your Child

The new study doesn’t prove that getting less sleep directly increases the risk of type 2 diabetes, which often develops gradually over several years. It could be that children who sleep less also don't eat as well, for example.

Still, says Nicole S. Glaser, M.D., a pediatric endocrinologist at U.C. Davis Health, “the study on sleep duration and risk of type 2 diabetes in children is important because it tells us that we should be looking into the connection between the two more closely.”

The potential protective impact of an extra hour of sleep each night may be small, says Glaser, but these small effects can add up over time—especially when combined with other strategies to reduce the risk of type 2 diabetes, such as maintaining a healthy weight and being active.

The key takeaway, says Owen, is that if you can encourage healthy sleeping habits from an early age—a low-cost and simple intervention—it could potentially lower the risk of developing type 2 diabetes as a child or even later in life. 

How to Set Your Child Up for a Restful Night’s Sleep

The new study doesn’t suggest some magic number of hours children need to sleep each night to minimize their risk of developing diabetes, says Owen. But official guidelines from the American Academy of Sleep Medicine and the American Academy of Pediatrics say children 6 to 12 years old should be getting 9 to 12 hours of sleep each night. (Younger children need even more.)

Some signs that your child might be sleep deprived are: 1) falling asleep in the car frequently; 2) having a hard time waking up for school; or 3) acting unusually tired, cranky, irritable, aggressive, emotional, hyperactive, or easily distracted.

Here are some strategies from the UCLA Sleep Disorders Center and other experts to help your elementary-school-aged child get a good night’s sleep.

Limit screen time before bed. The lure of tablets, smart phones, and other electronics is stronger than ever. But some studies suggest that the blue light they emit causes levels of the sleep-inducing hormone melatonin to drop, making it harder for your kids to fall asleep. Make sure electronics are tucked away and the TV is turned off at least an hour or two before bedtime, the National Sleep Foundation suggests.

Keep your bedtime routine consistent. Sticking with a nightly routine can help breed good sleeping habits. Whether you read to your child, play a low-activity game, or sing a lullaby before bed, do it at the same time every night—ideally 10 to 30 minutes before they should be asleep. The American Academy of Pediatrics’ “Brush, Book, Bed” program has helpful tips for getting started on a nighttime routine with kids up to 6 years old.

Be firm, but not threatening, with bedtime. The goal is to make sleeping an enjoyable experience for your child, which will allow them to fall asleep more easily. If they learn that they can delay bedtime with requests for another story, a hug, or a glass of juice, they’ll realize that bedtime can always be put off.

Avoid caffeine late in the day. Caffeine can take up to 6 hours to wear off, and kids are more prone to its effects. The American Academy of Pediatrics says children should avoid caffeinated beverages such as energy drinks and soda in general, but these—along with chocolates, painkillers, and coffee ice cream, all of which sometimes contain caffeine—can be especially problematic later in the day.