Study Links Sleep Deprivation, Obesity
Weight-loss experts have a novel prescription
for people who want to shed pounds: Get some sleep. A very large
study has found a surprisingly strong link between the amount
of shut-eye people get and their risk of becoming obese.
Those who got less than four hours
of sleep a night were 73 percent more likely to be obese than
those who got the recommended seven to nine hours of rest, scientists
discovered. Those who averaged five hours of sleep had 50 percent
greater risk, and those who got six hours had 23 percent more.
"Maybe there's a window of opportunity
for helping people sleep more, and maybe that would help their
weight," said Dr. Steven Heymsfield of Columbia University and
St. Luke's-Roosevelt Hospital in New York.
He and James Gangwisch, a Columbia
epidemiologist, led the study and are presenting results this
week at a meeting of the North American Association for the Study
They used information on about
18,000 adults participating in the federal government's National
Health and Nutrition Examination Survey, or NHANES, throughout
the 1980s. The survey includes long-term follow-up information
on health habits, and researchers adjusted it to take into account
other things that affect the odds of obesity, like exercise habits,
so that the effects of sleep could be isolated.
It seems "somewhat counterintuitive"
that sleeping more would prevent obesity because people burn fewer
calories when they're resting, Gangwisch said.
But they also eat when they're
awake, and the effect of chronic sleep deprivation on the body's
food-seeking circuitry is what specialists think may be making
the difference in obesity risks.
"There's growing scientific evidence
that there's a link between sleep and the various neural pathways
that regulate food intake," Heymsfield said.
Sleep deprivation lowers leptin,
a blood protein that suppresses appetite and seems to affect how
the brain senses when the body has had enough food. Sleep deprivation
also raises levels of grehlin, a substance that makes people want
It also hurts "executive function"
the ability to make clear decisions, said Dr. Philip Eichling,
a sleep and weight-loss specialist at the University of Arizona
who also is medical director of the Canyon Ranch, a spa in Tucson
that offers health and weight management programs, especially
for business executives.
"One of my treatments is to tell
them they should move from six hours to seven hours of sleep.
When they're less sleepy, they're less hungry," he said.
Eichling had no role in the new
study but said it gives important evidence for a long-suspected
theory in the field. Americans average only a little more than
six hours of sleep a night, and one report a few years ago even
suggested that the growing prevalence of sleep deprivation might
be responsible for the growing obesity epidemic, he said.
Reference Source 89
Nov 16, 2004