by Patricia Neighmond 由Patricia neighmond

For thousands of years, beginning with philosophers like Hippocrates, Socrates and Plato, fasting was recommended for health reasons.千百年來，開始與哲學家一樣，希波克拉底，蘇格拉底和柏拉圖，空腹有人建議，為了健康理由。 The Bible writes that Moses and Jesus fasted for 40 days for spiritual renewal.聖經寫道：摩西和耶穌禁食四十天的精神重建。

To understand how the body reacts to a lack of food, you could start by looking at what happens to newborns.了解如何身體反應缺乏食物，你可以開始看會發生什麼變化新生兒。 Newborns can’t sleep through the night because they need to eat every few hours.新生兒不能睡眠，通過夜間，因為他們要吃飯，每幾個小時。 They don’t produce enough glycogen, the body’s form of stored sugar, to make energy.他們這樣做不能產生足夠的糖原，身體的形式儲存糖，使能源。

“Glycogen is necessary for thinking; it’s necessary for muscle action; it’s necessary just for the cells to live in general,” says Dr. Naomi Neufeld, an endocrinologist at UCLA. “糖原是必要的思想;它所需的肌肉動作，它的必要只為細胞住在一般博士說： ”納奧米neufeld ，內分泌在加州大學洛杉磯分校。

Neufeld says most adults need about 2,000 calories a day. neufeld說，大多數的成年人大約需要2000卡路里天。 Those calories make energy, or glycogen.這些熱量，使能源，或糖原。 Neufeld says it doesn’t hurt — it might even help the body — to fast or stop eating for short periods of time, say 24 hours once a week, as long as you drink water. neufeld說，它沒有傷害-它甚至可能幫助身體-快速或者停止進食時間很短的時間，例如24小時，每星期一次，只要你喝水。

“You re-tune the body, suppress insulin secretion, reduce the taste for sugar, so sugar becomes something you’re less fond of taking,” Neufeld says. “您重新調整機構，壓制胰島素分泌，減少的味道，糖，所以糖變成您少喜歡以” neufeld說。

Eventually the body burns up stored sugars, or glycogen, so less insulin is needed to help the body digest food.最終身體燒傷了儲存的糖，或糖原，所以較少胰島素是需要幫助身體消化食物。 That gives the pancreas a rest.這使胰腺休息。 On juice diets recommended by some spas, you may lose weight, but your digestive system doesn’t get that rest.對果汁的飲食建議的一些溫泉，您可能會失去的重量，但您的消化系統並沒有得到休息。

Mark Mattson, a scientist with the National Institute on Aging, says that when we convert food into energy, our bodies create a lot of byproducts we could do without, including free radicals.馬克mattson ，一位科學家與國家老齡問題研究所指出，當我們轉換食物轉化為能源，我們的身體創造了很多的副產品，我們可以做的沒有，包括自由基。

“These free radicals will attack proteins, DNA, the nucleus of cells, the membranes of cells,” Mattson says. “這些自由基會攻擊蛋白質， DNA ，細胞核的細胞，膜細胞， ” mattson說。 “They can damage all those different molecules in cells.” “他們可以損害所有這些不同的分子在細胞” 。

And even if you don’t fast, Mattson says that simply limiting the calories you consume may be beneficial.甚至如果你不快速， mattson說，簡單地限制熱量的消耗，你可能是有益的。 He points to studies where rats and mice were fed every other day.他指出，研究中大鼠和小鼠分別餵食每隔一天。 Compared with those fed normal daily diets, there was a reduction in disease among the rats that were severely restricted in their food intake.相對於美聯儲正常的日常飲食，有一個在減少疾病之間的老鼠受到嚴格限制在其食物攝入量。 Mattson says those findings hold promise that humans could also benefit from partial fasting. mattson說，這些調查結果進行承諾，人類還可以受益於局部禁食。

Mattson thinks partial fasting has numerous benefits, from improving glucose regulation, which can protect against diabetes, to also lowering blood pressure. mattson認為，部分空腹有很多的好處，從改善糖調節，它可以防止糖尿病，又降低了血液的壓力。 Some animal studies have also shown that partial fasting has very beneficial effects on the brain, protecting against Alzheimer’s, Parkinson’s and stroke.一些動物研究還表明，部分空腹已十分有益的影響，對大腦，防止老年癡呆症，帕金森氏和中風。

Partial fasting may even extend lifespan because eating less sends a message to the cells of the body that they should conserve and use energy more efficiently.部分禁食，甚至可能延長壽命，因為吃少傳送訊息到細胞的身體，他們應該保護和能源使用更有效率。

“When they’re exposed to a mild stress, [the body’s cells] sort of expect that maybe this is going to happen again,” Mattson says. “當他們接觸到一種輕微的壓力， [人體細胞]排序的期望，也許這將會是再次發生， ” mattson說。 “So maybe next time I may have to go longer without food, so I’d better be able to deal with that when it comes on.” “因此，也許下一次我可能會去再沒有食物，所以我最好能夠處理與當談到對” 。

Mattson says that process is similar to the way muscles get built up when they’re stressed by exercise. mattson說，這個過程是類似的方式肌肉得到建立起來時，他們所強調的行使。 Mattson adds that because complete fasting is difficult to study and there is little actual research comparing people who fast with those who don’t, it’s not clear whether complete fasting (water only) is also beneficial. mattson補充說，因為完整的禁食是很難的研究和有一點實際的研究比較快的人與那些不這樣做，現在還不清楚是否完成禁食（水只） ，也有利於。

Proponents say small, short-term studies find that complete fasting lowers blood pressure and reduces cancer risk.倡議者說，小，短期研究發現，完全禁食，降低血壓和減少患癌症的風險。 But Dr. Naomi Neufeld worries that complete fasting could be harmful.但博士納奧米neufeld擔心完全禁食，可有害的。 After the first few days of liquid only, the body uses up all its stored glucose to make energy.後的頭幾天的液體，身體利用了其所有儲存的葡萄糖使能源。 And then it turns to other sources, including fat and muscle.然後輪流其他來源，包括脂肪和肌肉。

“The main tissue that’s the target in long-term fasting is muscle, because muscle has readily available amino acids which can be converted to glucose right away,” Neufeld says. “主要的組織的目標是在長期禁食是肌肉，因為肌肉有現成的氨基酸，其中可轉換為葡萄糖的權利消失， ” neufeld說。 “In that way, your brain is never deprived of needed glucose.” “以這種方式，你的大腦是從來沒有被剝奪了所需要的葡萄糖” 。

The problem, Neufeld says, is that when muscle breaks down, potentially toxic proteins are released.這個問題， neufeld說，就是當肌肉壞了，可能有毒的蛋白質釋放。 These proteins are partly composed of nitrogen, and too much nitrogen in the body can be toxic to the kidneys and liver.這些蛋白質部分組成的氮，和太多的氮在體內的可毒性，腎臟和肝臟。 That’s when starvation is officially under way.這時候，飢餓是正式正在進行之中。