Obesity Linked to Quantity of Sleep

People who sleep fewer than six hours a night - or more than nine - are more
likely to be obese, according to a study that is one of the largest to show
a link between irregular sleep and big bellies.
The study also linked light sleepers to higher smoking rates, less physical
activity and more alcohol use.
The research adds weight to a stream of studies that have found obesity and
other health problems in those who don't get proper shuteye, said Dr Ron
Kramer, a physician and a spokesman for the Academy of Sleep Medicine.
"The data is all coming together that short sleepers and long sleepers don't
do so well," Kramer said. The study is based on door-to-door surveys of
87,000 adults from 2004 through 2006 conducted by the NCHS.
Such surveys can't prove cause-effect relationships, so - for example - it's
not clear if smoking causes sleeplessness or if sleeplessness prompts
smoking, said Charlotte Schoenborn, the study's lead author.
It also did not account for the influence of other factors, such as
depression, which can contribute to heavy eating, smoking, sleeplessness and
other problems.
Smoking was highest for people who got under six hours of sleep, with 31 per
cent saying they were current smokers. Those who got nine or more hours also
were big puffers, with 26 per cent smoking.
The overall smoking rate is about 21 per cent. For those in the study who
sleep seven to eight hours, the rate was lower, at 18 per cent.
Results were similar, though a bit less dramatic, for obesity: About 33 per
cent of those who slept less than six hours were obese, and 26 per cent for
those who got nine or more. Normal sleepers were the thinnest group, with
obesity at 22 per cent.
For alcohol use, those who slept the least were the biggest drinkers.
However, alcohol use for those who slept seven to eight hours and those who
slept nine hours or more was similar.
In another measure, nearly half of those who slept nine hours or more each
night were physically inactive in their leisure time, which was worse even
than the lightest sleepers and the proper sleepers. Many of those who sleep
nine hours or more may have serious health problems that make exercise
difficult.
Many elderly people are in the group who get the least sleep, which would
help explain why physical activity rates are low. Those skimpy sleepers who
are younger may still feel too tired to exercise, experts said.
Stress or psychological problems may explain what's going on with some of
the lighter sleepers, experts said.
Other studies have found inadequate sleep is tied to appetite-influencing
hormone imbalances and a higher incidence of diabetes and high blood
pressure, noted James Gangwisch, a respected sleep researcher.
"We're getting to the point that they may start recommending getting enough
sleep as a standard approach to weight loss and the prevention of obesity,"
said Gangwisch, who was not involved in the study. [SMH]