If you're what researchers call a short sleeper (measured by how long you sleep each night—5.5 to 6 hours or less qualifies you), you'll have trouble losing weight, no doubt about it. In a 7-year study of 7,022 middle-aged people, Finnish researchers found that women who reported sleep problems were more likely to experience a major weight gain (defined as 11 pounds or more).
You know that sleep and weight gain may be linked, but why is that? Here's what the earth-shattering new research has revealed, and why lack of sleep could be stalling your ability to lose weight and keep it off:
Sleep Less, Burn Less
In a study at the department of neuroendocrinology at the University of Lübeck, Germany, published in the American Journal of Clinical Nutrition, researchers had a group of men sleep for 12 hours a night but didn't allow them to sleep the next night, and then had them eat an opulent buffet the following morning. Then the researchers measured the subjects' energy expenditure—the calories you burn just by being. When the men were sleep-deprived, their general energy expenditure was 5 percent less than it was when they got a good night's sleep, and their post-meal energy expenditure was 20 percent less.
Sleep Less, Eat More
In research presented at the American Heart Association's 2011 Scientific Sessions, it was shown that women who got only 4 hours of sleep at night ate 329 additional calories the next day than they did after they slept 9 hours. (Men ate 263 calories more.) In another study published in the American Journal of Clinical Nutrition, 11 volunteers spent 14 days at a sleep center on two occasions. During one period, they slept 5.5 hours a night, and during the other, they slept 8.5 hours. When the subjects were sleep-deprived, they increased their nighttime snacking and were more likely to choose high-carbohydrate snacks.
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