Are Sleepy Kids at Risk for Obesity?
Children Who Slept the Least Had Greater Risk of Being Overweight
March 30, 2006 -- Kids today tend to sleep less and weigh more than their
peers growing up just a few decades ago. Now intriguing new research suggests
this is no coincidence.
The survey of grade-schoolers in Quebec showed that the less the children
slept the more likely they were to become overweight.
Children who routinely got 10 hours or less of sleep a night had almost 3.5
times the risk than those who got 12 hours or more. Lack of sleep was a bigger
risk factor for overweight and obesity in the study than any other known
contributor, including parental obesity, family income, or time spent in front
of the television or computer.
Although the observational findings must be confirmed in clinical trials,
study co-author Angelo Tremblay, PhD, says the evidence that sleep deprivation
plays a role in obesity is mounting.
"It is ironic that part of the solution to obesity might lie in sleep,
the most sedentary of all human activities," he says. "In light of this
study's results, my best prescription against obesity in children would be to
encourage them to move more and to make sure they get enough sleep."
Twice as Many Overweight Kids
The rise in childhood obesity has been identified as a major public health
concern in the industrialized world. There are twice as many overweight kids
between the ages of 6 and 11 in the United States today than there were 20
years ago, and the number of teens who are overweight or obese has more than
At the same time, studies suggest that sleep deprivation is an increasing
problem among children and adolescents.
While research also suggests that sleep deprivation may contribute to
obesity among adults, few studies have investigated sleep patterns and weight
The study by Tremblay and colleagues from Quebec's Laval University included
422 grade-school students in Quebec. There were equal numbers of boys and girls
with an average age of 6.5 for the girls and 6.6 for the boys. Researchers
measured the children's weight, height, and waist size, and information on
sleep patterns and lifestyle was obtained through phone interviews with
One in five boys in the study and about one in four girls were found to be
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