Researchers followed 68,183 middle-aged women for 16 years and found
that those who slept 5 hours or less per night were one third more likely
to gain weight than those who slept for 7 hours.
Moreover, researchers found that the weight gain was substantial with
some women even gaining 33 pounds or more.
The associations between sleep
duration and weight gain persisted even after controlling
for factors such as physical activity and calorie consumption in both
groups.
The findings, presented earlier this year at a medical conference and
published in the American Journal of Epidemiology, furthers the evidence
that sleep habits affect a person's weight.
The exact reasons for association between sleep duration and weight
gain aren't clear but some research suggests that sleep deprivation alters
hormones involved in appetite control and metabolism.
Also it's possible that people who sleep fewer hours either eat more
or, because of fatigue, and exercise less often.
