根據(jù)哈佛醫(yī)學(xué)院（Harvard Medical School）最新的一項(xiàng)研究顯示，只需要在12-16小時(shí)內(nèi)不進(jìn)食就可以幫助你快速的調(diào)整你的睡眠周期，這項(xiàng)新的發(fā)現(xiàn)將能夠有效的幫助人們應(yīng)對(duì)飛行時(shí)差綜合癥（jet lag）或是熬夜加班造成的睡眠周期紊亂。
科學(xué)家已經(jīng)發(fā)現(xiàn)我們的晝夜感是由我們暴露在光線下的時(shí)間決定的，現(xiàn)在他們發(fā)現(xiàn)當(dāng)我們感到饑餓時(shí)，第二個(gè)“食物時(shí)鐘”也可以影響我們的晝夜感，而這一機(jī)制或許就是造成哺乳動(dòng)物在他們感到饑餓時(shí)無(wú)法入睡的原因。
這項(xiàng)研究的首席研究員Clifford Saper解釋說(shuō)：
第二時(shí)鐘最妙的地方就在于它可以覆蓋我們的主時(shí)鐘，也就是說(shuō)你應(yīng)該可以在一天之內(nèi)將你的生物鐘調(diào)整到一個(gè)新的時(shí)區(qū)。
通常人們需要花費(fèi)一周左右的時(shí)間才能將他們的生物鐘調(diào)整到一個(gè)新的時(shí)區(qū)，想想這種新的“食物時(shí)鐘”可以幫助你在一天之內(nèi)倒好時(shí)差，這真是難以置信。
該如何使用這個(gè)技巧？
你只需要保證在你醒來(lái)之前的12-16個(gè)小時(shí)不要吃任何東西就行了，一旦你開(kāi)始再次進(jìn)食，你的內(nèi)部時(shí)鐘就已經(jīng)完成了重置，它會(huì)將這看做是新的一天的開(kāi)始，你的身體也會(huì)將你吃早餐的時(shí)間看做是一個(gè)新的“早晨”。
舉個(gè)例子，如果你想要在凌晨2點(diǎn)醒過(guò)來(lái)，你應(yīng)該從前一天的上午10點(diǎn)到下午2點(diǎn)之間開(kāi)始禁食，并且一直持續(xù)到你在凌晨2點(diǎn)醒過(guò)來(lái)，然后你需要好好的吃上一頓豐盛的早餐，現(xiàn)在，你的身體就已經(jīng)準(zhǔn)備好迎接一個(gè)全新的“早晨”了。
再舉一個(gè)例子：如果你從洛杉磯旅行到東京，你只需計(jì)算好你在東京的第一頓早餐的時(shí)間，然后從這個(gè)時(shí)間往前推12-16個(gè)小時(shí)，保證不要進(jìn)食就可以了。
另外，你還可以同時(shí)使用其它一些促進(jìn)睡眠以及保持精力的技巧，這樣可以幫助你更快的調(diào)整你的生物鐘到一個(gè)新的時(shí)區(qū)。
科學(xué)機(jī)制：為什么這會(huì)有效？
就同我們進(jìn)化史上的所有事情一樣，這也是因?yàn)檫m者生存的原則，下面是對(duì)Saper的研究成果的簡(jiǎn)單總結(jié)：
http:///2011/06/12/how-to-naturally-reset-your-sleep-cycle-overnight/
根據(jù)研究，”對(duì)于小型哺乳動(dòng)物，尋找食物是它們每天的頭等大事，因?yàn)榧词怪皇丘I上幾天，在自然環(huán)境下，這也有可能會(huì)變成死亡威脅“。
“因此，為了應(yīng)對(duì)這種情況，在經(jīng)受一段時(shí)間的饑餓之后，動(dòng)物必須要能夠通過(guò)它們的第二“主時(shí)鐘”來(lái)快速調(diào)整它們的行為模式，以增強(qiáng)它們?cè)诘诙斓南嗤瑫r(shí)間獲得食物的機(jī)會(huì)。”
Fuller認(rèn)為，發(fā)生在小型哺乳動(dòng)物身上的這種強(qiáng)制調(diào)整睡眠模式的行為只是一種求生機(jī)制，研究表明，只需要一個(gè)饑餓周期就足以覆蓋傳統(tǒng)的由光線決定的生理周期。
“這個(gè)新的時(shí)鐘可以有效的幫助動(dòng)物調(diào)整它們的睡眠周期，以提升他們獲取食物的機(jī)會(huì)”
”16小時(shí)的禁食已經(jīng)足夠形成一個(gè)新的時(shí)鐘周期了“，Saper說(shuō)。
所以，在這種情況下，只需要避免在飛機(jī)上攝入任何食物，然后在你著陸后立即尋找食物，應(yīng)該可以幫助你調(diào)整——并且避免因?yàn)轱w行時(shí)差綜合癥（jet lag）而導(dǎo)致的不適”，CBS（引用自發(fā)表在09年5月22日科學(xué)雜志上的研究報(bào)告）。
How to Naturally Reset Your Sleep Cycle in One Night
Not eating for 12-16 hours can help people quickly reset their sleep-wake cycle, according to a new study from the Harvard Medical School. This discovery can drastically improve a person's ability to cope with jet lag or adjust to working late shifts.
Scientists have long known that our circadian rhythm is regulated by our exposure to light. Now they have found a second "food clock" that takes over when we are hungry. This mechanism probably evolved to make sure starving mammals don't go to sleep when they should be foraging for food.
The lead researcher Clifford Saper explains:
The neat thing about this second clock is that it can override the main clock ... and you should just flip into that new time zone in one day.
It usually takes people a week to fully adjust to a new time zone or sleeping schedule. To think that this new "food clock" hack can help you change your internal clock in one day is mind boggling.
How does it work?
Simply stop eating during the 12-16 hour period before you want to be awake. Once you start eating again, your internal clock will be reset as though it is the start of a new day. Your body will consider the time you break your fast as your new "morning."
For example, if you want to start waking up at 2:00 am, you should start fasting between 10:00 am or 2:00 pm the previous day, and don't break your fast until you wake up at 2:00 am. Make sure you eat a nice healthy meal to jumpstart your system.
Another example: If you are travelling from Los Angeles to Tokyo, figure out when breakfast is served in Tokyo, and don't eat for the 12-16 hours before Tokyo's breakfast time.
Why does this work?
Like everything else in our evolutionary history, it has to do with survival:
"For a small mammal, finding food on a daily basis is a critical mission. Even a few days of starvation, a common threat in natural environments, may result in death," the study said.
"Hence, it is adaptive for animals to have a secondary "master clock" that can allow the animal to switch its behavioral patterns rapidly after a period of starvation to maximize the opportunity of finding food sources at the same time on following days."
The shift is a survival mechanism in small mammals that forces them to change their sleeping patterns, Fuller suggests. One starvation cycle is enough to override the traditional light-based circadian clock, the study suggests.
"This new timepiece enables animals to switch their sleep and wake schedules in order to maximize their opportunity of finding food."
"A period of fasting with no food at all for about 16 hours is enough to engage this new clock," says Saper.
"So, in this case, simply avoiding any food on the plane, and then eating as soon as you land, should help you to adjust — and avoid some of the uncomfortable feelings of jet lag." CBC (quoting study published in the May 22 issue of Science.
