Are Sleepy Kids at Risk for Obesity?
Children Who Slept the Least Had Greater Risk of Being Overweight
Twice as Many Overweight Kids continued...
One in five boys in the study and about one in four girls were found to be overweight.
When compared with children reporting 12 to 13 hours of sleep a night, those that got 10.5 to 11.5 hours were more than 40% more likely to be overweight or obese, and those that got eight to 10 hours were almost 3.5 times as likely to be above normal weight.
The findings are reported in the latest online issue of the International Journal of Obesity.
Hormones May Hold the Key
If there is a link between sleep and weight regulation, many researchers now say that hormones may explain it. University of Chicago researchers have shown that sleep and lack of sleep affect production of two hormones that regulate appetite.
Their studies suggest that sleep deprivation was linked to lower levels of the hormone leptin, which decreases hunger, and higher levels of the hunger-producing hormone ghrelin.
Robert D. Vorona, MD, who has also studied sleep patterns and obesity in adults, says the research is fairly consistent but still inconclusive. He notes, for example, that there is no consensus on how much sleep people actually need to lower their risk of becoming overweight or to help them lose weight.
"What we can say is that the studies to date show an association between restricted sleep and obesity," Vorona, who is the Eastern Virginia Medical School associate professor of medicine, tells WebMD. "What we can't say is that these studies definitely prove a causal relationship."
In a poll conducted in 2000, the National Sleep Foundation reported that the average American gets just under seven hours of sleep each night -- about an hour less than is optimal for most people and about 90 minutes less than most Americans slept in the 1900s.
Vorona says chronic sleep deprivation alters mood, affects performance, and is a major risk factor for automobile and work-related accidents.
"There are plenty of reasons to get a good night's sleep," he says. "And it is very possible that [weight control] is yet another one."