One Week， No Food 轻断食：一次特别的禁食经历

S+Abbas+Raza++译+阿诺

为了保持完美的身材，相信多数人都曾尝试过各种瘦身法。要论近来在全球哪种瘦身法最热，那当属“轻断食”了。这种禁食方法是指一周或一个月中有几天停止进食，只靠喝白水或蔬果汁来维持身体所需，以达到瘦身、健体的目的。这样的方法真能达到所宣传的效果吗？文中作者用一周的时间体验了一把轻断食，我们来看看他禁食的效果如何。

It all began in March last year when I read an article by Steve Hendricks in Harpers magazine titled “Starving Your Way to Vigour.” Hendricks examined the health benefits of fasting1）， including long-term reduced seizure2） activity in epileptics3）， lowered blood pressure in hypertensives4）， and weight loss. He also mentioned significantly increased longevity in rats that are made to fast. Most interesting was his tale of undertaking a 20-day fast himself， during which he shed more than 20 pounds and kept it off for the two years since. I was fascinated， and I started reading more about fasting afterwards， although at the time I had no intention of doing it myself.

The benefits of fasting have been much in the news again， in part due to a best-selling book from the UK： The Fast Diet： Lose Weight， Stay Healthy， and Live Longer by Dr Michael Mosley and Mimi Spencer. Mosley is a BBC health and science journalist who extols5） the benefits of “intermittent fasting.” There are many versions of this type of fasting that are currently the subject of various research programmes， but Mosley settled on the 5：2 ratio—in every week， two days of fasting， and five days of normal eating. Mosleys claim is that such a “feast or famine” regime closely matches the food consumption patterns of pre-modern societies， and our bodies are designed to optimise such eating. Mosley says that he himself lost 20 lbs in nine weeks on the diet. He also says that he feels much more energetic since.

Inspired by Mosley and Hendricks， I delved into research on fasting online. I happen to be a mild hypertensive myself and for various reasons have been off my blood pressure medication for a couple of months. I thought I might try fasting as an experiment， to see if it made any difference to my blood pressure， but also out of sheer curiosity about what the experience would be like. My wife said she would try it， too.

We decided on a seven-day fast—somewhere between Hendricks experience and Mosleys recommendation. The plan was to go a full week without eating or drinking anything except water. Lest our bodies react to this insult by trying to slow down our metabolisms6）， and we end up just lying around and not getting anything useful done all week， we also planned to stay energetic by engaging in vigorous physical exercise for at least a couple of hours daily during the fast. Neither one of us had ever done anything of the sort before.

Since my wife had a weeks break in February from her work， we decided to try our fast then. Our preparation was pretty minimal. I would keep a journal in which I would record my weight， blood pressure， activities and， several times a day， just note how I was feeling. We bought some emergency supplies in case one or both of us ended up feeling ill or fainting： some energy drinks， a couple of bars of Swiss milk chocolate， some fruit， and some bread and cheese， and put them in the refrigerator.

On our final day before beginning， we measured our weight， blood pressure， pulse rate， and waist size. My wife and I dont normally eat breakfast. That day we just had a light lunch and in the evening we had an early dinner of chicken， potatoes， and brown rice. And some chocolate pudding. And then we stopped eating.

The scientific data on the benefits of fasting are still thin and far from conclusive7）： Mark Mattson， head of the National Institute on Agings neuroscience laboratory， thinks it is possible that fasting is a mild form of stress that stimulates the bodys cellular defences against molecular damage. And even intermittent fasting can increase the bodys sensitivity to insulin8）， thereby decreasing the risks of diabetes and heart disease. Some nutritionists are sceptical， and especially worry about the dangers of compensatory overeating in the times one is not fasting. Even if we dont yet have enough data for clear conclusions， there was enough material from my research to intrigue me to try it for myself.

Our weeklong fast was a little unusual as we also engaged in strenuous9） exercise every day. Sometimes a little too strenuous： One day we did a 14 km trek through Alpine snow at a place called the Rodenecker Alm near Italys border with Austria. This was almost four hours of climbing and descending after three days of total fasting， and it left us quite exhausted and sore. But the odd thing was that to both of us it actually felt easier in this fasting state than it would have under normal conditions. So one does indeed seem to have a lot of physical energy while fasting， as Mosley has argued.

Things were not perfect， however. My wife had to break the fast at the end of day six because she neither felt nor looked well. I did make it through the whole seven days without any physical problems but I was psychologically exhausted by the end of it and euphoric10） that it was over. In everything that I had read about fasting， days two to four were supposed to be the most difficult. I had also worried about getting headaches or other physical discomfort， and especially about being unable to get restful sleep： I thought I might be awakened by hunger pangs. As it happens， none of those troubled me. Which isnt to say it wasnt an odd experience.

First of all， every single one of the seven days felt exactly the same： Mornings were completely fine and I felt pretty much as I normally do until about lunchtime. I tried to pack in any work， especially work that required mental concentration， into this period of each day. After midday， I became a little fidgety and found it hard to concentrate on anything. I had much more than usual amounts of physical energy and did all kinds of household chores happily. But my mind flitted from one thing to the next， and my reactions were slowed down very noticeably by evening. If my wife asked me a question， it took about five seconds for it to register and another five before I could formulate and deliver a reply.

So the days were hazy11） at times， but very bearable. Not so the evenings. By far the worst time was between 6 pm and 10 pm in the evenings. It was in this window12） every day that my wife and I both felt a physical and mental unease resulting in great difficulty in just passing the time. We tried to watch TV or movies but it was hard， and the evening seemed strangely empty.

In fact， the biggest surprise was just how much more time we had on our hands. I was struck by how much of the day I normally spend attending to my digestive needs： thinking about what I would have for lunch or dinner； shopping for groceries； cooking； then actually eating， washing dishes， cleaning up， even moving ones bowels13）. Eliminating the simple act of eating frees up much more time than youd think. In addition to the couple of hours of daily exercise we kept up throughout， we took long walks in the mountains， did crosswords， surfed the net and fooled around14） on Facebook， and we still always had more time to fill. I realised that meals provide needed punctuation to the day， and without them our days seemed strangely lacking in structure.

So what about the medical benefits？ In the end， both throughout and after the fast， my blood pressure remained at exactly the same， slightly elevated level it had been before I started. So much for controlling it by fasting， at least for me. I lost 11 lbs （5 kg） over the week and gained 7 lbs （3 kg） back within three days. I experienced a phenomenal increase in physical energy but at the expense of a lack of mental concentration. These effects lasted only while I was actually fasting： One day after breaking the fast， I felt completely normal， with the same appetite and level of physical energy as usual.

Did I feel any different from normal in the days immediately after the end of the fast or since？ No， not really. Would I do it again？ I doubt it. Though it was fun in its own peculiar way. Well … maybe. But I think Ill at least wait for more controlled clinical evidence to come in.

一切始于去年3月我在《哈泼斯》杂志上读到的一篇由史蒂夫·亨德里克斯写的题为《饿出你的活力来》的文章。亨德里克斯调查了禁食对健康的益处，包括在长期内减少癫痫患者的发病次数、降低高血压患者的血压以及减轻体重。他还提到，被动禁食的老鼠的寿命得到了显著延长。最有趣的部分是他自己禁食20天的经历，在此期间他的体重减掉了20多磅，并在其后的两年内一直保持这一体重。我为此感到着迷，之后开始阅读更多有关禁食的文章，虽然当时我还没有亲身尝试的打算。

新闻里又开始大谈禁食的好处了，部分归因于一本来自英国的畅销书：由迈克尔·莫斯利博士和米米·斯潘塞撰写的《轻断食：正在横扫全球的瘦身革命》。莫斯利是BBC的健康和科学栏目记者，对“间歇性禁食”的益处赞不绝口。这种禁食方式有多种不同的版本，目前各类研究项目都在对之进行研究，而莫斯利选定以5：2的比例进行禁食——每周禁食两天，其他五天正常饮食。莫斯利声称，这种“饥饱交替”的进食法与近代之前人们的饮食模式极为接近，而人体的设计可以最大限度地利用这种进食方式。……