Hey there science cravers, Julian here for "DNews."

嗨！你們這些科學狂人！我是 DNews 的 Julian。

A lot of diet fads are very specific about what you should eat,

許多飲食潮流都指出你們應該吃些什麼，

but hardly any of them talk about when you should eat.

但是幾乎很少提過你們該在哪時候進食。

That’s because for years now the conventional wisdom has basically been that the overall number of calories you eat versus how many you burn is what’s important.

那是因為多年下來，大部分人都認為真正重要的是所攝取的總熱量相較於總消耗的熱量。

But a few studies have challenged this idea.

但是，有幾項研究挑戰了這樣的想法。

One in 2013 published in the International Journal of Obesity,

一項是在發表在 2013 年的國際肥胖期刊中，

followed 420 obese or overweight adults who were trying to lose weight over 20 weeks.

該研究追蹤了420 位嘗試減重 20 周以上的肥胖或過胖者。

Those who ate their largest meal before three p.m. on average lost almost two kilograms more than those who ate after,

那些在下午三點以前吃完份量最多的一餐的人，平均比那些在下午三點以後吃的人還瘦了兩公斤，

even if caloric intake and amount of exercise was the same.

儘管他們的卡路里攝取和運動量都是相同的。

But why should that be the case?

但是，為什麼會出現這種情況？

Well, it’s possible the same meal may be treated differently depending on where your body is in it’s circadian rhythm.

這個可能性是，同樣的一餐在不同的生理時鐘作用下，在體內可能會被消化得不同。

Yes, the 24 hour cycle that we usually just associate with our sleep schedule also has an effect on how our bodies absorb and digest food.

是的，我們常常認為睡眠與二十四小時生理時鐘較有關連性，但是這樣的生理時鐘也會影響我們身體吸收與消耗食物的過程。

So, eating out of our normal rhythm can contribute to weight gain,

所以，在我們不正常的規律下進食會導致體重的增加，

according to Kelly Allison of the University of Pennsylvania School of Medicine’s Center for Weight and Eating Disorders.

這是來自賓州大學的體重以及飲食失調的醫學中心人員 Kelly Allison 所提出的。

Wow, that is one bloated title.

哇...這個職稱實在有夠長。

So, what’s causing us to eat out of our regular rhythms?

所以，到底什麼原因導致我們在不正常的規律下進食？

Society, man.

老兄！是這個社會。

The way we work has caused a sort of social jet lag,

我們工作的方式已經形成了一種社會時差，

where the time we have available to eat doesn’t match the time it would be most ideal to eat.

我們能夠吃飯的時間並不符合真正理想的進食時間。

We’re skipping breakfast more,

我們越來越常省略掉早餐，

and our meal times are becoming irregular as we focus on getting work done or picking up the kids from school.

而且我們會為了要完成工作或是接小孩放學，吃飯時間因而變得不規律。

We may actually be intentionally fighting the circadian rhythm,

我們實際上故意違背了生理時鐘，

when it causes cortisol and adrenaline to drop off around 3 p.m.

進而使得我們的皮質醇和腎上腺素大約在下午三點時下降。

To stay off the sleepiness, some of us indulge in something high in sugar or fat.

為了要抵抗這樣的昏昏欲睡，有些人會食用高糖或是高脂肪類的食物來滿足自己。

According to Pamela Peeke, an assistant professor at the University of Maryland School of Medicine, this will raise our insulin levels and we’ll crave sugar later.

根據馬里蘭大學醫學部的助理教授 Pamela Peeke 指出，這樣的行為會導致我們的胰島素升高，而之後我們會吃更多的甜食。

Our circadian rhythm is at odds with our modern lifestyle in other ways too.

我們的生理時鐘在其他方面也是與現在的生活型態互相對峙的。

When we first evolved, food wasn’t readily available in refrigerators when we woke up.

在人類進化過程的一開始，並不是一醒來就可以在冰箱裡拿到食物的。

So, it’s possible that as the day progresses, the food we eat is more apt to turn into fat.

所以，也許是隨著時代進步，我們所攝取的食物更有可能堆積為脂肪。

So, the next day we have a convenient reserve of energy and we don’t have to worry about our first meal.

因此，到了隔天我們還儲有能量，而不用擔心第一餐要吃些什麼。

That’s the hypothesis of Steven Shea, director of the Oregon Institute of Occupational Health Sciences.

這是來自美國奧勒岡職業健康科學機構的經理 Steven Shea 所假設的。

Shea also notices in his research that people tend to be hungrier later in the day, possibly as part of this evolutionary adaptation.

Shea 也在研究中注意到，人們在較晚時會感受到飢餓，那可能是身體適應演化的一部分。

Combine that with the fact that since artificial light we stay up later than ever,

結合此一事實，自從有了人造光線後，我們熬夜熬得比任何時候都還要晚，

and now have ready access to food, and the result is some people can’t resist a late night bite.

而且現今也有各式各樣的管道來取得食物，導致有些人無法抗拒吃消夜。

Furthermore, if you are grabbing food late at night, you’re more likely to make an unhealthy choice.

除此之外，如果你晚上吃消夜，都會選擇較為不健康的食物。

You may do it out of convenience, because it’s easier to grab a bag of chips than make a salad, or you might do it out of mental exhaustion.

你可能只是出於方便才這麼做，因為伸手抓包洋芋片比大費周章地做沙拉更簡單、更不費力。

If you’ve spent the whole day on your best dietary behavior, late at night you’re more willing to let yourself slip,

如果你已經花一整天來維持你最好的飲食行為，到了晚上你較容易會放縱自己，

or even reward yourself with something fatty, salty, sweet, and delicious.

甚至會獎勵自己吃一些較為油、鹹、甜、和美味的食物。

Even the researchers who study this admit that chrononutrition is an under-explored topic, with few studies done so far and many of them relying on mice.

甚至這方面的研究員認為計時營養學尚未被徹底研究，迄今為止的研究很少，而且多數都是拿老鼠來做研究。

While the studies we’ve cited point to a link between late day eating and weight gain,

而這些我們已經提到過的研究指出，吃宵夜和變胖是有關聯的，

plenty of others support the orthodox view that net calorie count is the most important factor.

其他很多人支持的傳統方法認為淨卡路里計算是最重要的因素。

Once again, more research is needed.

不過呢，還是需要更多研究來證實這樣的理論。

I just hope it involves cake.

我只希望它會有蛋糕的相關研究。

If you love food science and food in general, click here now to check out our friends over at "Eater".

如果你們整體而言喜歡食物科學以及食物，就點擊這裡，收看我們的朋友在 Eater 上的影片。

So, the sort of two strategies to reduce sodium intake.

所以，有兩種方式來降低鈉的攝取量。

One would be to find a substitute enhancer. Another would be to ship the population down.

一個方式是找到適當的味道代替品。另一個方式是降低用量。

There is no molecule that tastes purely salty other than sodium chloride, and another one lithium chloride,

除了氯化鈉，沒有一個分子可以完全是鹹的，而另一個是氯化鋰，

but lithium chloride poisons, so that is not a good salt substitute.

但氯化鋰是有毒的，所以並不適合做為鹽的替代品。

So, have you tried shifting your caloric intake to earlier in the day? How did that work out for you?

所以，你們有試過提早你們的進食時間嗎？結果如何呢？

Let us know in the comment. Subscribe for more, and I will see you next time on "DNews".

留言讓我們知道。歡迎訂閱來學到更多，我們下回 DNews 再見！