A study published Monday found that people who sleep less tend to be fat, and experts said it's time find if more sleep will fight obesity.

"We've put so much emphasis on diet and exercise that we've failed to recognize the value of good sleep," said Fred Turek, a physician at Northwestern University.

Monday's study from Eastern Virginia Medical School in Norfolk covered 1,000 people and found that total sleep time decreased as body mass index -- a measure of weight based on height -- increased.

Men slept an average of 27 minutes less than women and overweight and obese patients slept less than patients with normal weights, it said. In general the fatter subjects slept about 1.8 hours a week less than those with normal weights.

"Americans experience insufficient sleep and corpulent bodies. Clinicians are aware of the burden of obesity on patients," the study said.

"Our findings suggest that major extensions of sleep time may not be necessary, as an extra 20 minutes of sleep per night seems to be associated with a lower body mass index," it added.

"We caution that this study does not establish a cause-and-effect relationship between restricted sleep and obesity (but) investigations demonstrating success in weight loss via extensions of sleep would help greatly to establish such a relationship."

The study was published in the Archives of Internal Medicine along with an editorial by Turek and Northwestern colleague Joseph Bass commenting on it and related research.

In an interview with Reuters, Turek said some studies have shown sleep deprivation causes declines in an appetite suppressing protein hormone called leptin, and increases in another hormone that causes a craving for food. In addition neuropeptides in the brain governing sleep and obesity appear to overlap, he said.

Obesity has been rising dramatically in developed countries and reached epidemic levels in the United States, it added, leading to a variety of health problems. 

本周一（1月10日）发布的一项研究表明睡眠不足的人易发胖。专家们表示现在是时候调查一下睡得多是否有助于减肥。

美国西北大学的医学教授弗莱德·塔瑞克说：“我们一直过份强调节食和锻炼，以至于忽略了良好睡眠的作用。”

周一，位于美国弗吉尼亚州诺福克市的东维吉尼亚医学院发布了这份研究。对1000名受试者的研究显示累计睡眠时间和体重指数刚好成反比，体重指数是一种以身高为基准来衡量体重的方法。

该研究显示男性的睡眠时间平均比女性少27分钟，而肥胖病人比正常体重的病人睡眠时间少。总的来说，体态肥胖的受试者每周比正常体重的受试者少睡约1.8小时。

该研究指出：“美国人普遍睡眠不足﹑体型超标。医生们已经认识到肥胖给病人带来的负担。”

同时该研究还显示：“我们的调查结果表明没有必要大量增加睡眠时间，每晚多睡20分钟似乎有助于降低体重指数。”

“我们要提醒（大家）的是这项研究的结果并不足以证明节制睡眠和肥胖之间的因果关系，（然而）调查显示延长睡眠时间确实可以成功减轻体重，这对于证明这一因果关系非常有帮助。”

该研究结果发表在美国《内科学文献》期刊上，塔瑞克和西北大学的同行约瑟夫·贝斯共同对上述研究结果及其相关研究发表了评论。

在接受路透社采访时，塔瑞克说已经有研究表明睡眠不足会导致“瘦体素”分泌减少，而另一种增强食欲的荷尔蒙分泌增多，“瘦体素”是一种抑制食欲的蛋白质荷尔蒙。此外，他还说大脑中调节睡眠和肥胖的神经肽似乎重合在一起。

该研究还提到，近年来发达国家肥胖症的发病率以惊人速度增长，在美国肥胖已成为一种流行病，并且引发多种健康问题。