Women who fail to get enough shut-eye each night risk gaining weight, a Cleveland-based researcher reported.

    In a long-term study of middle-aged women, those who slept 5 hours or less each night were 32 percent more likely to gain a significant amount of weight (adding 33 pounds or more) and 15 percent more likely to become obese during 16 years of follow-up than women who slept 7 hours each night.

    This level of weight gain -- 15 kg, or 33 pounds -- is "very clinically significant in terms of risk of diabetes and heart disease," Dr. Sanjay Patel of Case Western Reserve University said.

    Women who slept 6 hours nightly were 12 percent more likely to experience major weight gain and 6 percent more likely to become obese compared with those who slept 7 hours each night.

    The 68,183 women in the study provided information in 1986 on their typical night's sleep and reported their weight every 2 years for 16 years.

    Women who said they slept for 5 hours or less each night, on average, weighed 5.4 pounds more at the beginning of the study than those sleeping 7 hours.

    After accounting for the influence of age and weight at the beginning of the study, women who slept 5 hours or less each night gained about 2.3 pounds more during follow-up than those who slept 7 hours nightly. Women who got 6 hours of shut-eye each night gained 1.5 pounds more than those who slept 7 hours nightly.

    The researchers analyzed the diets and physical activity levels of the women, but failed to find any differences that could explain why women who slept less weighed more. "We actually found that women who slept less, ate less," Patel said.

    "In terms of exercise, we saw a small difference in that women who slept less exercised slightly less than women who slept more but it didn't explain the magnitude of our findings," Patel said.

    All in all, it seems that diet and exercise are not accounting for the weight gain in women who sleep less, Patel concluded.

    It's possible that sleeping less may affect changes in a person's basal metabolic rate -- the number of calories burned when at rest, Patel said.

    Another possible contributor to weight regulation that's come to light recently is called "non-exercise associated thermogenesis" or NEAT, which refers to involuntary activity such as fidgeting or standing instead of sitting. It may be, Patel said, that if people who sleep less, also move around or "fidget" less.

    克利夫兰研究人员说，在夜间缺乏睡眠的人很有可能增加体重。

    这项长期跟踪中年妇女的调查显示，每晚睡眠少于5个小时的妇女比睡眠足够7个小时的妇女更容易变胖。大量增加体重（大约33磅或者更多）的比率要高出32%，16年后会走进肥胖人群的比率高出15%。

    凯斯西储大学萨耶·帕特尔说15公斤或者33磅的体重增长在医学上已经很可怕了，可能引起糖尿病和心脏病。

    每天晚上睡6个小时的妇女明显增加体重的几率比每晚睡7个小时的妇女要高出12个百分点，变肥胖的几率要高出6个百分点。

    68183位妇女参加了此项调查，1986年报告了自己的夜间睡眠状况，在之后的16年中，每两年汇报一次体重状况。

    初期调查显示，每晚睡眠少于5个小时的妇女比7个小时的妇女平均体重多出5.4磅。

    除去年龄的影响和调查初期的体重增长情况，在之后的调查中发现睡眠少于5个小时的妇女比7个小时的妇女体重要多增加2.3磅。每晚睡6个小时的妇女比七个小时的多增加1.5磅。