A Coke's not all you need
吃甜食真能提神吗？
It happens from time to time that after a whole morning of studying, you are tired in the afternoon. It's then that you might want to have something sweet, perhaps a Coke or a chocolate bar to lift your mood. After all, it's believed that a "sugar rush" gives us energy.
在经过一整个上午的学习之后，你下午时常会感到困倦。这时候你或许就想吃点甜食，比方说，一罐可乐或者一块巧克力来提神。毕竟，很多人都认为吃甜食能够补充能量。
But a study published in Neuroscience and Biobehavioral Reviews in April suggests that sugar can make us feel worse rather than boost our moods.
但《神经学与生物行为评论》四月刊登的一项研究显示，糖分并不能提神，而是会让我们感觉更糟。
The German and UK researchers collected data from 31 studies involving nearly 1,300 adults. They studied the effect of sugar on various aspects of mood, including anger, alertness, depression and tiredness.
来自德国和英国的研究人员从31项研究中收集了近1300名成年人的数据。他们研究了糖分对各方面情绪所带来的影响，如愤怒、警惕性、抑郁以及疲倦等等。
They found that people who have too much sugar become more tired and less alert within an hour, and that these feelings become more intense over time.
他们发现，摄入过多糖分的人在一小时内会更容易感到疲倦，警惕性也会下降，而这些感觉会随着时间的流逝变得更加强烈。

According to researchers, when people take in sugar, their blood sugar levels rise rapidly, leading to a burst of energy and a short "feel good" period. However, as they begin to digest the sugar, their blood sugar levels decrease quickly, leading to a bad feeling.
研究者们认为，在摄入糖分后，人们的血糖水平会迅速升高，令人精神大振，暂时“感觉不错”。但随着人们开始消耗糖分，血糖水平也会迅速下降，从而产生不适感。
To remain on a "high", people are likely to eat more and more sugar until they become addicted to it. As with caffeine, this prevents the body from relaxing, leaving people feeling tired and less alert.
为了保持“情绪高涨”，人们便很有可能吃更多的甜食，直到上瘾。和咖啡因一样，这会让我们的身体无法放松，令人感到疲倦并且警惕性下降。
But the study's findings needn't make us think we must give up sweet food altogether. According to the World Health Organization, it is healthy to have the sugars found naturally in fruit, vegetables and milk, so long as they make up less than 5 percent of our daily total energy intake.
但这项研究发现并不意味着我们必须都戒掉甜食。世界卫生组织认为，摄入水果、蔬菜、牛奶中的天然糖分有益健康，只要这些糖分的摄入量不超过每日摄取总能量的5%即可。
So the next time you feel tired and can't concentrate, perhaps you should think twice before you bite into a chocolate bar. Maybe a spot of exercise at midday would be a better idea!
因此，下一次当你感到疲倦，无法集中注意力的时候，或许你得重新考虑下要不要吃巧克力了。中午运动一下或许是个更棒的选择！