Sleeping Less Linked To Weight Gain

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Sleeping Less Linked To Weight Gain

http://www.medicalnewstoday.com/medicalnews.php?newsid=43970

Women who sleep 5 hours or less per night weigh more on average than

those who sleep 7 hours, according to a study to be presented at the

American Thoracic Society International Conference on May 23rd.

The study found that women who slept for 5 hours per night were 32%

more likely to experience major weight gain (defined as an increase

of 33 pounds or more) and 15% more likely to become obese over the

course of the 16-year study compared with women who slept 7 hours.

Women who slept for 6 hours were 12% more likely to have major weight

gain and 6% more likely to become obese compared with women who slept

7 hours a night.

The study included 68,183 middle-aged women who were enrolled in the

Nurses Health Study. They were asked in 1986 about their typical

night's sleep, and were then asked to report their weight every 2

years for 16 years.

On average, women who slept 5 hours or less per night weighed 5.4

pounds more at the beginning of the study than those sleeping 7 hours

and gained an additional 1.6 pounds more over the next 10 years.

" That may not sound like much, but it is an average amount--some

women gained much more than that, and even a small difference in

weight can increase a person's risk of health problems such as

diabetes and hypertension, " said lead researcher Sanjay Patel, M.D.,

Assistant Professor of Medicine at Case Western Reserve University in

Cleveland, OH.

Dr. Patel noted that this is by far the largest study to track the

effect of sleep habits on weight gain over time. " There have been a

number of studies that have shown that at one point in time, people

who sleep less weigh more, but this is one of the first studies to

show reduced sleep increases the risk of gaining weight over time. "

The researchers looked at the women's diets and exercise habits to

see if they could account for part of the findings. " Prior studies

have shown that after just a few days of sleep restriction, the

hormones that control appetite cause people to become hungrier, so we

thought that women who slept less might eat more. But in fact they

ate less, " Dr. Patel said. " That suggests that appetite and diet are

not accounting for the weight gain in women who sleep less. "

The researchers also asked women about how much they participated in

exercise activities such as running, jogging or playing tennis. But

they didn't find any differences in physical activity that could

explain why women who slept less weighed more.

" We don't have an answer from this study about why reduced sleep

causes weight gain, but there are some possibilities that deserve

further study, " Dr. Patel said. " Sleeping less may affect changes in

a person's basal metabolic rate (the number of calories you burn when

you rest). Another contributor to weight regulation that has recently

been discovered is called non-exercise associated thermogenesis, or

NEAT, which refers to involuntary activity, such as fidgeting or

standing instead of sitting. It may be that if you sleep less, you

move around less, too, and therefore burn up fewer calories. "