Middle-aged women who sleep five or fewer hours each night weigh an average of 5.5 lbs more than those who sleep for at least seven hours.
Boulder, Colorado (PRWEB) May 24, 2011
WellWise.org's mission is to inform the public about issues that affect health. Obesity, especially in the United States, is epidemic. There are many causes, some still being discovered, but studies suggest one of them almost certainly is lack of sleep.
Over the last century, the average night’s sleep has gone from nine hours a night to six and three-quarters hours, research shows. This reduction in sleep time is paralleled by the increase in body weight in the U.S. population. One possible cause: According to Dr. Jacob Teitelbaum, one of WellWise’s numerous health bloggers, sleep is responsible for many weight and appetite-controlling hormones, such as growth hormone, leptin, phrelin and ghrelin.
Just over the past four decades, daily sleep duration has decreased by one and a half to two hours. The proportion of young adults sleeping less than seven hours per night has more than doubled, from 15.6 percent in 1960 to 37.1 percent in 2002.
A study presented at the American Thoracic Society International Conference in 2006 showed that middle-aged women who sleep five or fewer hours each night weigh an average of 2.5 kg (5.5 lbs.) more than those who sleep for at least seven hours.
In the Quebec Family Study, a six-year study designed to determine the relationship between sleep duration and weight, researchers followed 276 adults aged 21 to 64. The investigators compared weight gain relative to three categories of sleep duration ― short (5-6 hours), average (7-8 hours), and long (9-10 hours). Compared with average-duration sleepers, short-duration sleepers gained 4.4 pounds more in a six-year period. At six years, short-duration and long-duration sleepers were 35 percent and 25 percent more likely to experience a 12-pound weight gain, respectively, compared to those who slept seven to eight hours a night.
Compared with average-duration sleepers, short-duration sleepers had a 27 percent increased risk for the development of obesity, and long-duration sleepers had a 21 percent increase in risk. Adjustment for caloric intake and physical activity did not affect these connections.
So how much sleep is optimal for staying thin? Between seven and nine hours is considered best. Less than seven hours increases the risk of obesity approximately 30 percent and adds an extra five pounds on average.
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