Have you ever wondered why some days all you want to do is snack？

Under normal circumstances， we feel hungry when we have burnt up the food we have eaten as energy and our blood sugar and insulin levels begin to drop. Ghrelin， a hormone connected to appetite， then communicates this to the brain， which is how we feel the need to eat.

But all sorts of things can interfere with this process.

你有沒有想過這個問題：為什么有時候你總想吃東西？

正常情況下，當我們的身體把所攝入的食物轉化為能量消耗之后，我們的血糖和胰島素水平開始降低，這時我們就會感到饑餓。然后，胃饑餓素——一種跟食欲相關的激素——將這個信息傳達給大腦，這樣我們就會感到需要吃東西了。

但是各種各樣的事情都會干擾這個過程。

According to a study by researchers at Columbia University in the US， those who are sleep-deprived eat almost 300 calories a day more than those who get enough sleep.

This is because levels of the hormone ghrelin， which tells the brain we need to eat， increase when we dont get enough sleep.

The Columbia researchers noted that the women who didnt get enough sleep took in more fat rising by around 30g on sleep-deprived days—four times as much as the average increase for men.

根據美國哥倫比亞大學研究人員的一項研究，那些睡眠不足的人每天攝入的熱量幾乎比那些睡眠充足的人多300卡路里。

這是因為當我們睡眠不足時，告訴大腦我們需要進食的胃饑餓素的水平會升高。

哥倫比亞大學的研究人員指出，睡眠不足的女性在睡眠不足的日子里攝入的脂肪增加了約30克——是男性平均增加量的四倍。

Troubled times

有麻煩時

In a study， people who were primed to expect “tough times ahead” ate more food than people who listened to neutral messages.

Its thought that hearing about troubled times causes a survival instinct to kick in， leading to cravings for high-calorie snacks such as chocolate.

在一項研究中，那些得知不久會遭遇“艱難時期”的人會比獲得中性信息的人吃得更多。

人們認為，一聽說“有麻煩了”，人的生存本能會被激發(fā)，這也就導致了對巧克力等高熱量零食的渴求。

Food cravings

對食物的渴望

Tempted by that extra biscuit？ Then just enjoy it—as researchers have found that when you feel guilty about a pleasurable experience， the guilt itself becomes pleasurable， so encouraging you to do it more.

“If we consider something a naughty pleasure， it can psychologically drive the appetite and the guilt may make you want to eat more，” says Cary Cooper， at the University of Lancaster.

The appetite center of the brain also lies very close to the area governing mood—the limbic system—which is why changes in the way we feel may affect appetite.

還想再吃一塊小餅干？那么，想吃就吃吧，因為研究人員發(fā)現，當你對某次愉快的體驗感到內疚時，內疚本身也會變得愉悅，進而鼓勵你再次去做這件事。

蘭卡斯特大學的卡里·庫珀說：“如果我們認為某件事會帶來不妥的愉悅感，這會在心理上促進食欲，而且這種內疚可能會讓你想要吃得更多?！?/p>

大腦中的食欲中樞非?？拷榫w控制區(qū)域——邊緣系統——這就是為什么我們的情緒變化會影響食欲。

Mobiles blue light

手機藍光

The blue light emitted by devices such as smartphones and tablets may give a boost to your appetite.

Research has found that your appetite continued to increase when you are exposed to the light.

It also altered peoples metabolism. Blood tests showed that the blue-light subjects had higher insulin and glucose levels.

One possible explanation is that bright blue light at night confuses our body clock， which has a role in controlling when we feel the need to eat.

智能手機和平板電腦等設備發(fā)出的藍光可能會促進你的食欲。

研究發(fā)現，在藍光的照射下，你的食欲會持續(xù)增加。

藍光的照射還會改變人們的新陳代謝過程。血液測試顯示，在藍光照射下的測試者的胰島素和葡萄糖水平都更高。

一種可能的解釋是，夜間明亮的藍光會干擾我們的生物鐘，而生物鐘可以控制我們什么時候感到需要進食。

Word Study

interfere /'?nt?'f??（r）/ v. 妨礙;干擾

She never allows her personal feelings to

interfere with her work.

prime /pra?m/ v. 事先指點;使（某人）做好準備

Did you prime her with what to say？

instinct /'?nst??kt/ n. 本能;天性

craving /'kre?v??/ n. 強烈的愿望;渴望

guilty /'ɡ?lti/ adj. 感到內疚的

emit /i'm?t/ v. 發(fā)出;散發(fā)