A late night not only creates dark circles under the eyes and a grumpy temper - it can cause weight gain too, according to a new study. 

　　据一项的研究调查显示，熬夜不仅带给我们难看的黑眼圈和坏脾气，同时还会使得体重飙升。

　　Scientists have discovered a lack of sleep can drastically slow the metabolism down which causes the body to use less energy for simple tasks like breathing and eating, after depriving male students of sleep. 

　　在减少了男性学生的睡眠时间后，科学家们发现，睡眠不足将大大放慢人体新陈代谢的速度，直接导致类似呼吸与进食这样简单的活动所消耗的热量随之降低。

　　The results, reported in the American Journal of Clinical Nutrition, add to evidence that sleep loss can promote weight gain - not just by boosting hunger but also by slowing the rate at which calories are burned. 

　　这篇发表在美国灵床营养学期刊上的报告再次证实睡眠不足将引发人体发胖，这不仅是因为睡眠不足将增加饥饿感，同时还因为消耗的热量也减少了。

　　The study suggests that getting plenty of sleep might prevent weight gain, said Christian Benedict of Uppsala University in Sweden, who led the study. 

　　来自瑞典乌鲁萨拉大学的学者Christian Benedict主导了这次的研究，他表示充足的睡眠将有助于避免发胖。

　　'Our findings show that one night of sleep deprivation acutely reduces energy expenditure in healthy men, which suggests sleep contributes to the acute regulation of daytime energy expenditure in humans,' he wrote. 

　　“我们的研究结果显示，整夜不眠将降低健康男性身体所消耗的热量，这说明睡眠会影响到人体在白天消耗热量的情况。”

　　To identify how a lack of sleep might have these effects, Benedict and his colleagues put 14 male university students through a series of sleep 'conditions' 

　　为了证实缺乏睡眠将对身体产生的影响，Benedict与他的同时使14名男大学生经历了不同的睡眠情况。

　　They subjected them to curtailed sleep, no sleep, and normal sleep over several days, then measured changes in how much they ate, their blood sugar, hormone levels and indicators of their metabolic rate. 

　　他们了经历减少睡眠时间、不睡觉、正常的睡眠不同情况数天之后，研究者测量了他们的食量、体内激素的水平以及新陈代谢水平的变化。

　　They found that just a single night of missed sleep slowed metabolism the next morning, reducing energy expenditure for tasks like breathing and digestion by 5 per cent to 20 per cent, compared with the morning after a good night's sleep. 

　　研究者发现，哪怕是熬夜一个晚上，第二天新陈代谢也会减缓，与一晚安眠的睡眠相比，在呼吸、消化方面所消耗的热量将降低百分之五到百分之而是。

　　The young men also had higher morning levels of blood sugar, appetite-regulating hormones such as ghrelin, and stress hormones such as cortisol after sleep disruption. 

　　这些年轻男性在清晨的血压水平也会变高，分泌的生长素和应激激素量也发生了变化。

　　Still, the sleep loss did not boost the amount of food the men consumed during the day. 

　　不过睡眠不足并未影响他们在白天时对于食物的消耗。

　　A number of studies have observed that people who sleep five hours or less are more prone to weight gain and weigh-related diseases such as type-2 diabetes. 

　　之前的研究也显示每晚睡眠时间不无五小时的人群发胖的可能性更大，同时还容易患上与体重超标相关的疾病，比如说罹患2型糖尿病的风险就高出了不少。

　　But those studies do not prove that sleep loss causes weight gain. 

　　不过之前的研究都没能证明睡眠不足是体重增加的原因。

　　Experts said that factors such as lifestyle and diet might add to obesity risks and that it was not clear that sleep deprivation led to obesity. 

　　导师认为人们的生活方式以及饮食习惯将增加肥胖的可能性，但不能确定睡眠与肥胖之间的直接关系。

　　Sanford Auerbach, head of the Sleep Disorders Center at Boston Medical Center, noted that sleep deprivation is a complex issue, with medication and other issues influencing sleep as well, and urged that the new findings be kept in context. 

　　波士顿医疗机构睡眠障碍中心的负责人Sanford Auerbach指出，睡眠不足是一个复杂的问题，药物和其他因素都会对睡眠产生影响，因此这一发现并不能推而广之。

　　'They showed that we adapt to sleep deprivation and that some of these adaptations could theoretically contribute to obesity,' he said, adding that it's not clear how chronic sleep loss influences hormone levels. 

　　“研究显示人们会缓慢的适应睡眠不足的情况，在这一过程中可能会伴随肥胖的出现”，不过他也表示，目前仍然不能确定长期睡眠不足对于荷尔蒙水平会造成怎样的影响。

　　The National Sleep Foundation recommends that adults get about seven to nine hours of sleep each night. 

　　美国国家睡眠基金会建议成年人每晚应有7到9小时的睡眠时间。