We all know that eating badly, and eating too much, are associated with gaining weight. New research has shown that another factor is also important -what time of day you eat. A new study, published in The American Journal of Clinical Nutrition, showed that eating later in the evening was associated with a higher percentage of body fat.

我们都知道：吃的差和吃的多都会导致体重增加。新研究已表明，另一个因素同等重要--每天什么时候吃。《美国临床营养杂志》上刊出的一项新研究表明，晚上稍晚一点吃东西与更高的体脂比例相关。

But it also found that the overall effects all came down to your own personal biological clock rather than the actual time. Researchers collected data from 110 college students over 30 days to observe their sleep times and eating habits. They also looked at when subjects released melatonin - the sleep hormone¹ - to determine where their circadian rhythms (body clocks) were at.

但研究还发现整体影响因素得归结于个人的生物钟，而不是实际时间。研究人员在30天内收集110名大学生的数据，以观察他们的睡觉时间和饮食习惯。他们还观察了受试者何时释放褪黑激素--睡眠激素--以确定他们的昼夜节律（身体时钟）。

They then examined the relationship between body clock setting, body mass index (BMI), and the timing² of food consumption. The team expected to see that individuals who ate closer to their melatonin onset³ - which is usually occurs just before sleep - would have a higher percentage of body fat.

之后他们检查了身体时钟设定、身体质量指数和进食时间的关系。该团队估计，临近褪黑激素释放点吃东西的人--通常在睡觉之前--会有更高的体脂比例。

Results showed that they were right, and those who had high body fat percentages consumed most of their calories shortly before going to bed, when melatonin levels were high. However, this didn't mean they found a relationship between eating later and gaining weight per se, rather that timing of when you consume calories, relative to your own biological timing, may be an important factor for your health.

研究结果表明他们的猜测是正确的，那些体脂比例高的人大多数的热量都是在睡前摄入的，那时的褪黑激素是最高的。然而，这并不意味着他们发现了吃的晚与体重增长本身的关系，而是发现了什么时候摄入热量，与自己的生物钟相比较，可能是影响健康的重要因素。

"We believe that our findings highlight that when you eat may be just as important as what you eat," lead author Andrew W. McHill, researcher with the Division of Sleep and Circadian Disorders⁴ at Brigham and Women's Hospital in Massachusetts, told Business Insider.

"我们认为我们的研究强调了什么时候吃可能与吃什么一样重要，"首席作者安德鲁W.麦克希尔对Business Insider杂志说道，他还是马萨诸塞州妇女医院和布里格姆Sleep and Circadian Disorders部门的研究员。

"We actually hypothesise that the mechanism⁵ driving this result is a lower amount of energy expended⁶ to break down food that is consumed during the night, as we have shown that to be true during controlled laboratory studies."

"我们实际上假设导致这一结果的机制是夜晚摄入食物时，分解食物的能量更低，在控制实验研究中，这一假设被证明是正确的。"

As with every study, there were a few limitations, such as the fact that participants may have under-reported how many calories they consumed, or may have changed their eating habits while they knew they were being tracked.

每一项研究都有一些限制，比如受试者可能少报了他们摄入的热量，或者可能在知道自己被追踪的情况下改变了自己的饮食习惯。

There was also only one night where melatonin levels were assessed, so slight changes could not be identified.

同时，我们只在一个晚上评估了褪黑激素水平，所以无法确定轻微的变化。