by Patricia Neighmond 由Patricia neighmond

For thousands of years, beginning with philosophers like Hippocrates, Socrates and Plato, fasting was recommended for health reasons.千百年来，开始与哲学家一样，希波克拉底，苏格拉底和柏拉图，空腹有人建议，为了健康理由。 The Bible writes that Moses and Jesus fasted for 40 days for spiritual renewal.圣经写道：摩西和耶稣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.了解如何身体反应缺乏食物，你可以开始看会发生什么变化新生儿。 Newborns can’t sleep through the night because they need to eat every few hours.新生儿不能睡眠，通过夜间，因为他们要吃饭，每几个小时。 They don’t produce enough glycogen, the body’s form of stored sugar, to make energy.他们这样做不能产生足够的糖原，身体的形式储存糖，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;它所需的肌肉动作，它的必要只为细胞住在一般博士说： ”纳奥米neufeld ，内分泌在加州大学洛杉矶分校。

Neufeld says most adults need about 2,000 calories a day. neufeld说，大多数的成年人大约需要2000卡路里天。 Those calories make energy, or glycogen.这些热量，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说，它没有伤害-它甚至可能帮助身体-快速或者停止进食时间很短的时间，例如24小时，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. “您重新调整机构，压制胰岛素分泌，减少的味道，糖，所以糖变成您少喜欢以” neufeld说。

Eventually the body burns up stored sugars, or glycogen, so less insulin is needed to help the body digest food.最终身体烧伤了储存的糖，或糖原，所以较少胰岛素是需要帮助身体消化食物。 That gives the pancreas a rest.这使胰腺休息。 On juice diets recommended by some spas, you may lose weight, but your digestive system doesn’t get that rest.对果汁的饮食建议的一些温泉，您可能会失去的重量，但您的消化系统并没有得到休息。

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.马克mattson ，一位科学家与国家老龄问题研究所指出，当我们转换食物转化为能源，我们的身体创造了很多的副产品，我们可以做的没有，包括自由基。

“These free radicals will attack proteins, DNA, the nucleus of cells, the membranes of cells,” Mattson says. “这些自由基会攻击蛋白质， DNA ，细胞核的细胞，膜细胞， ” mattson说。 “They can damage all those different molecules in cells.” “他们可以损害所有这些不同的分子在细胞” 。

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说，简单地限制热量的消耗，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别喂食每隔一天。 Compared with those fed normal daily diets, there was a reduction in disease among the rats that were severely restricted in their food intake.相对于美联储正常的日常饮食，有一个在减少疾病之间的老鼠受到严格限制在其食物摄入量。 Mattson says those findings hold promise that humans could also benefit from partial fasting. mattson说，这些调查结果进行承诺，人类还可以受益于局部禁食。

Mattson thinks partial fasting has numerous benefits, from improving glucose regulation, which can protect against diabetes, to also lowering blood pressure. mattson认为，部分空腹有很多的好处，从改善糖调节，它可以防止糖尿病，又降低了血液的压力。 Some animal studies have also shown that partial fasting has very beneficial effects on the brain, protecting against Alzheimer’s, Parkinson’s and stroke.一些动物研究还表明，部分空腹已十分有益的影响，对大脑，防止老年痴呆症，帕金森氏和中风。

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，甚至可能延长寿命，因为吃少传送讯息到细胞的身体，他们应该保护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. “当他们接触到一种轻微的压力， [人体细胞]排序的期望，也许这将会是再次发生， ” mattson说。 “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，也许下一次我可能会去再没有食物，所以我最好能够处理与当谈到对” 。

Mattson says that process is similar to the way muscles get built up when they’re stressed by exercise. mattson说，这个过程是类似的方式肌肉得到建立起来时，他们所强调的行使。 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补充说，因为完整的禁食是很难的研究和有一点实际的研究比较，人谁的快速与那些谁不这样做，现在还不清楚是否完成禁食（水只） ，也有利于。

Proponents say small, short-term studies find that complete fasting lowers blood pressure and reduces cancer risk.倡议者说，小，短期研究发现，完全禁食，降低血压和减少患癌症的风险。 But Dr. Naomi Neufeld worries that complete fasting could be harmful.但博士纳奥米neufeld担心完全禁食，可有害的。 After the first few days of liquid only, the body uses up all its stored glucose to make energy.后的头几天的液体，身体利用了其所有储存的葡萄糖使能源。 And then it turns to other sources, including fat and muscle.然后轮流其他来源，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. “主要的组织的目标是在长期禁食是肌肉，因为肌肉有现成的氨基酸，其中可转换为葡萄糖的权利消失， ” neufeld说。 “In that way, your brain is never deprived of needed glucose.” “以这种方式，你的大脑是从来没有被剥夺了所需要的葡萄糖” 。

The problem, Neufeld says, is that when muscle breaks down, potentially toxic proteins are released.这个问题， neufeld说，就是当肌肉坏了，可能有毒的蛋白质释放。 These proteins are partly composed of nitrogen, and too much nitrogen in the body can be toxic to the kidneys and liver.这些蛋白质部分组成的氮，和太多的氮在体内的可毒性，肾脏和肝脏。 That’s when starvation is officially under way.这时候，饥饿是正式正在进行之中。