为什么感觉疲劳的时候特别想吃垃圾食品?

Demolishing half a packet of biscuits while staying up trying to finish an assignment, swapping fruit for a chocolate bar for your snack at work after an early start or longing for a croissant upon landing from a long-haul flight, there could now be a reason why you reach for the bad food after a bad night's sleep.
在熬夜办公时，你是否会轻而易举地消灭半包饼干？早起之后，你是否会把工作间餐的水果换成巧克力？或者是乘坐长途飞机后特别想要吃牛角面包？对于为什么晚上睡眠不好、白天就会想吃垃圾食品这个问题，这里可能会给你一种解释。

Researchers at Feinberg School of Medicine, Northwestern University in Chicago recently presented their results of a study looking into the effects of sleep deprivation upon high-calorific food consumption at the Cognitive Neuroscience Society's annual meeting in San Francisco, reports Science News.
最近，在洛杉矶的认知神经科学学会年度会议上，来自西北大学费恩伯格医学院的研究者们发表了关于缺乏睡眠对高热量食物摄入的影响的研究报告。

Participants were allocated different amounts of sleep, eight hours or four hours, and then their reaction to smells of high-calorific foods were tested.
这次试验中，参与者睡眠的时间各不相同，可能是8小时或4个小时，随后测试他们对于高卡路里食物的味道的反应。

Participants slept for both lengths of time, separated by a week of normal sleep.
每一位参与者都要参与这两种不同时长的睡眠实验，两次试验间隔一周的正常作息。

On the day after they either had full or partial sleep, participants rated the pleasantness and intensity of sweet and savoury high-calorific food smells such as crisps and cinnamon rolls. They were then asked to rate the smell of non-foods like fir trees.
在他们参加睡眠实验的第二天，参与者们被要求对包括薯片和肉桂卷这样的高糖、高盐、高卡路里食物打分，研究这些食物是否吸引人，能否让人感到愉悦。随后，参与者被要求给松木等非食品的气味打分。

Researchers found that those who were sleep-deprived had "specifically enhanced" brain activity to the food smells compared to when they had a good night's sleep.
研究人员发现，相较于睡眠充足的人，缺乏睡眠的人对于食物的气味有“强烈的”脑部活动。

The experiment supports the long-held association between sleep deprivation and excessive eating and weight gain.
这项实验论证了人们长久以来相信的缺乏睡眠和暴饮暴食、体重增加之间的关系。

So, if you want to stop reaching for the chocolate every day, perhaps a few extra hours sleep is all you need.
所以，如果你想要戒掉每天必吃的巧克力，你可能只需要额外几个小时的睡眠就可以了。