春天到了，夏天还会远吗？看着商场里琳琅满目的衣服，相信不少MM都暗下了减肥的决心。近期，美研究人员发现，睡眠时间关乎腹围，睡眠过少或过多，都会导致腹部脂肪(abdominal fat)明显增加。如果你也是减肥大军中的一员，首先就来看看怎样“科学睡眠”吧！

　　近期，一项研究结果称，睡眠时间关乎腰围，如果年轻人睡眠过少或过多，腰身脂肪在一段时期后会明显增加。 Younger adults who get either little sleep or a lot of it may see a greater expansion in their waistlines over time, a study published suggests。

　　研究人员发现，5年后，在年龄低于40岁的非洲裔美国人和拉丁裔美国人成年人中，每晚平均睡眠时间不超过5小时的研究对象将比平均睡眠6、7个小时的人积累更多腹部脂肪。 Researchers found that among black and Hispanic adults younger than 40, those who typically slept for five hours or less each night had a greater accumulation of belly fat over the next five years, versus those who averaged six or seven hours。

　　而每晚卧床时间不低于8小时的人同样会导致脂肪增加--但情况要比睡眠过少者乐观。 Those who logged eight hours or more in bed each night also showed a bigger fat gain - but it was less substantial than that seen in "short sleepers."

　　该研究结果刊载于医学杂志《睡眠》中。研究并没有证明睡眠过少或过多会直接导致过量脂肪增加。但它对其他研究做了数据支持和延伸--特别是缺少睡眠--将睡眠持续时间和体重增加、糖尿病、心脏病等做了关联。 The study, reported in the journal Sleep, does not prove that too little or too much sleep directly leads to excess fat gain. But the findings support and extend those of other studies linking sleep duration - particularly a lack of sleep - to weight gain and even to higher risks of diabetes and heart disease。

　　该研究以332名非洲裔美国人和775名拉丁裔美国人为研究对象，他们年龄在18至81岁之间。起初，所有报告都是关于他们的睡眠习惯、饮食、锻炼及其他生活因素。研究开始的时候，研究人员便用CT扫描方式测出研究对象腹部脂肪含量。五年后再做一次检测。 The study included 332 African-American and 775 Hispanic-American men and women ages 18 to 81. At the outset, all reported on their sleep habits, diets, exercise levels and other lifestyle factors. The researchers used CT scans to measure participants' abdominal fat, at the start of the study and again five years later。

　　研究发现，在年龄低于40岁的研究对象中，晚间平均睡眠时间不超过5小时的腹部脂肪增加量高于6至7小时平均睡眠的研究对象。 Among participants younger than 40, the study found, those who said they slept for five hours or less each night gained more belly fat than those who averaged six or seven hours of sleep。

　　前者的内脏脂肪增加32%，在6至7小时之间的增加13%，不低于8小时的增加22%。 On average, short sleepers showed a 32 percent gain in visceral fat, versus a 13 percent gain among those who slept six or seven hours per night, and a 22 percent increase among men and women who got at least eight hours of sleep each night。

　　皮下脂肪变化情形类似。 A similar pattern was seen with superficial abdominal fat。

　　美国北卡罗来纳州韦克福雷斯特大学医学院研究负责人克里斯滕·G·海尔斯通表示，该研究证实了睡眠习惯能够影响人们的体重和健康状况。“睡眠对你的身体健康很重要--并不仅在白天劳累的时候才有效。”她说。 The findings, according to lead researcher Dr. Kristen G. Hairston, of Wake Forest University School of Medicine in Winston-Salem, North Carolina, support the belief that sleep habits affect weight, and health in general. "Sleep is an important part of your overall health - not just in whether you're tired during the day," she said。

　　关于睡眠时间关乎腹部脂肪增加，有很多理论基础。 As for why sleep duration might affect abdominal-fat gain, there are several theories。

　　首先，睡眠时间可能间接影响脂肪增加：睡眠少可能使人感到疲倦，导致日间无力锻炼身体；与睡眠时间居中者相比，睡眠较多者花在运动上的时间少一些，因而脂肪增加多一些。 There may be indirect effects; people who get too little sleep may be too tired during the day to exercise, while those who spend a lot of time in bed may spend less time being active, relative to people who sleep fewer hours。

　　其次，研究表明，睡眠少可能影响与食欲有关的荷尔蒙水平，导致过量饮食。 Research also suggests that sleep loss alters people's levels of appetite-regulating hormones - which could, in theory, spur them to overeat。

　　再次，海尔斯通表示，心情抑郁也可能是一个原因：心情抑郁会影响人们的睡眠，抑郁本身与体重相关。但是，她和同事们没有研究对象抑郁症状的相关信息。 Depression, which often affects people's sleep and has been linked to weight gain, could also be a factor, Hairston noted. She and her colleagues had no information on study participants' depression symptoms。