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TED演讲：节食减肥到底有没有效果？
调查发现世界各国10岁少女中有80%的人表示过自己有通过节食减肥，但有健康专家指出在青少年时期通节食过的女孩，在成年后变胖的概率是没有节食的人的3倍！Sandra Aamodt博士通过自己的多年研究告诉我们，为什么节食减肥没有用，反而对身体有害？
演讲者：Sandra Aamodt
演说题目：节食减肥到底有没有效果？
This was me at age 13, when I started my first diet. I look at that picture now, and I think, you did not need a diet, you needed a fashion consult.But I thought I needed to lose weight, and when I gained it back, of course I blamed myself. And for the next three decades, I was on and off various diets. No matter what I tried, the weight I'd lost always came back. I'm sure many of you know the feeling.这是我13岁时候的样子，那是我开始第一次节食。现在我看着这张照片，我想我需要的不是节食，而是一名时尚顾问 。但当时我认为自己需要减肥，当我体重反弹回来的时候，我感到自责 。在接下来的三十年里，我开始又结束了各式各样的节食。无论我采取怎样的努力，我减去的体重总会反弹回来，我确信你们中的很多人能体会到这感觉。
As a neuroscientist, I wondered, why is this so hard? Obviously, how much you weigh depends on how much you eat and how much energy you burn. What most people don't realize is that hunger and energy use are controlled by the brain, mostly without your awareness. 作为一名神经科学家我很疑惑，为什么这如此困难？很显然，你的重量决定于你吃了多少和你消耗了多少能量 。但绝大部分人没有意识到的是，饥饿和消耗是由大脑掌控的。
Your brain does a lot of its work behind the scenes,and that is a good thing, because your conscious mind -- how do we put this politely? -- it's easily distracted. It's good that you don't have to remember to breathe when you get caught up in a movie. You don't forget how to walk because you're thinking about what to have for dinner.大多数情况下你甚至不会意识到，你的大脑在后台做了很多事。这很好，因为你的意识让我想个更有礼貌的说法---很容易被分散。当你专注于电影的时候，你不需要记得呼吸，亦可自由畅快地呼吸。你不会因为思考晚餐吃什么，而忘记如何行走。
Your brain also has its own sense of what you should weigh, no matter what you consciously believe. This is called your set point, but that's a misleading term, because it's actually a range of about 10 or 15 pounds.You can use lifestyle choices to move your weight up and down within that range, but it's much, much harder to stay outside of it. 你的大脑对于你的体重，有着自己的一套想法。无论你有意识地在想些什么，这被叫做你的设定值。但那是个误导人的术语，因为事实上它是一个范围，大约在10到15磅内浮动。你可以通过选择生活方式来改变你的体重，在这个范围内上下浮动。但是如果要超出这个范围，将是非常非常困难的。
The hypothalamus, the part of the brain that regulates body weight, there are more than a dozen chemical signals in the brain that tell your body to gain weight, more than another dozen that tell your body to lose it, and the system works like a thermostat, responding to signals from the body by adjusting hunger, activity and metabolism, to keep your weight stable as conditions change. That's what a thermostat does, right? 大脑的一个部分叫下丘脑，它调节着你的体重，你的大脑有十多种化学信号会告诉你的身体去增加体重。还有另外十多种信号会告诉你的身体去减重，这系统的工作原理就像恒温器。对身体接收到的信号做出反应，通过调节饥饿感、活动、新陈代谢，根据条件的变化，维持你的体重，这就是“恒温器”的作用，对吧？
It keeps the temperature in your house the same as the weather changes outside.Now you can try to change the temperature in your house by opening a window in the winter, but that's not going to change the setting on the thermostat, which will respond by kicking on the furnace to warm the place back up. 恒温器会根据房屋外部天气的变化不断调节，从而保持室内的温度恒。现在你可以通过在冬季打开一扇窗来调节室内的温度，但这个动作并不会改变恒温器的设置。恒温器对此的反应是打开火炉，把屋内的温度调节回温暖的状态。
Your brain works exactly the same way, responding to weight loss by using powerful tools to push your body back to what it considers normal. If you lose a lot of weight, your brain reacts as if you were starving, and whether you started out fat or thin, your brain's response is exactly the same. We would love to think that your brain could tell whether you need to lose weight or not, but it can't. If you do lose a lot of weight, you become hungry, and your muscles burn less energy. 你的大脑就是这样工作的。当你体重减轻的时候，它会用有效地工具让你的体重回归，回归到它认为正常的状态。如果你减重过多，你大脑的反应就是你快饿死了，无论你最初是胖还是瘦，大脑的反应都是一模一样的。我们非常希望我们的大脑可以感知我们是否需要减重，但它不能 。如果你真的减去了很多体重，你会感到很饿，你的肌肉会消耗更少的能量。
Dr. Rudy Leibel of Columbia University has found that people who have lost 10 percent of their body weight burn 250 to 400 calories less because their metabolism is suppressed. That's a lot of food. This means that a successful dieter must eat this much less forever than someone of the same weight who has always been thin.哥伦比亚大学的鲁迪利贝尔博士发现，那些减去体重10%的人们消耗的热量比未减重之前少250到400卡路里，因为他们的新陈代谢被抑制了。这些（热量）等于相当多的食物中所含的热量，这意味着一个成功的节食者，必须比和他相同体重的人少吃这么多食物，因为这个人一直都这么瘦。
From an evolutionary perspective, your body's resistance to weight loss makes sense. When food was scarce, our ancestors' survival depended on conserving energy, and regaining the weight when food was available would have protected them against the next shortage. Over the course of human history, starvation has been a much bigger problem than overeating. This may explain a very sad fact: Set points can go up, but they rarely go down.从进化的角度上讲，人的身体对于减重的抵制情有可原。当食物匮乏时，我们的祖先依靠身体中储存的能量生存；当食物充足时增加体重，将会确保他们在下一次食物短缺的情况下，能够生存下来。在人类历史进程中，饥饿一直是比吃撑更大的问题。这说明了一个非常可悲的事实，设定值可以增加，但几乎不会减少。
Now, if your mother ever mentioned that life is not fair, this is the kind of thing she was talking about. (Laughter) Successful dieting doesn't lower your set point. Even after you've kept the weight off for as long as seven years, your brain keeps trying to make you gain it back. If that weight loss had been due to a long famine, that would be a sensible response. 现在如果你妈妈跟你说，生活很不公平，这就是她所说的情形（笑声），节食成功并不会降低设定值，即便是你已经减轻体重。长达七年之久，你的大脑一直会让你把减掉的体重增回来。如果减重是由长时间饥饿造成的，这是合情合理的反应。
In our modern world of drive-thru burgers, it's not working out so well for many of us. That difference between our ancestral past and our abundant present is the reason that Dr. Yoni Freedhoff of the University of Ottawa would like to take some of his patients back to a time when food was less available, and it's also the reason that changing the food environment is really going to be the most effective solution to obesity.在充斥着得来速汉堡的现代世界，这种反应并不适用于大多数人，这就是过去我们祖先的生活和现代人富足的生活的差异。渥太华大学的约尼.弗雷德霍夫博士，想让他的一些病人回到食物不充足年代的原因，这也是为什么改变饮食环境将成为解决肥胖问题最有效的方法。
Sadly, a temporary weight gain can become permanent. If you stay at a high weight for too long, probably a matter of years for most of us, your brain may decide that that's the new normal.不幸的是，短暂的增重，可变为永久的增重。如果你长时间处于超重状态，对于我们大多数人来说可能是若干年，你的大脑就会觉得这是新的正常状态。
Psychologists classify eaters into two groups, those who rely on their hunger and those who try to control their eating through willpower, like most dieters. Let's call them intuitive eaters and controlled eaters. The interesting thing is that intuitive eaters are less likely to be overweight, and they spend less time thinking about food. Controlled eaters are more vulnerable to overeating in response to advertising, super-sizing, and the all-you-can-eat buffet. 心理学家把“吃货”分成两类。一类人靠本能的饥饿反应去吃；另一类人则是用意志去控制饮食。就像大多数节食者一样，我们称他们为本能型食者和自控型食者。有趣的是本型能食者，很少会超重，并且他们会花较少的时间思考吃什么东西。自控型食者则更容易受到广告，超大分量和自助餐的影响而造成饮食过量。
And a small indulgence, like eating one scoop of ice cream, is more likely to lead to a food binge in controlled eaters. Children are especially vulnerable to this cycle of dieting and then binging. Several long-term studies have shown that girls who diet in their early teenage years are three times more likely to become overweight five years later, even if they started at a normal weight。一个小小的放纵，比如一勺冰激凌，更有可能在自控型食者中，导致暴饮暴食的结果。在这种节食和暴饮暴食的循环下，孩子们特别容易受到伤害。一些长期研究表明，在青少年初期节食的女孩，在五年之后超重的可能性是未节食者的三倍，即便她们一开始体重正常。
And all of these studies found that the same factors that predicted weight gain also predicted the development of eating disorders. The other factor, by the way, those of you who are parents, was being teased by family membersabout their weight. So don't do that. 所有这些研究发现，预示体重增加的因素 ，也预示着饮食失调的产生。顺便说一下，请家长们注意了，另外一个因素是“因体重而被家庭成员取笑”所以别那样做。
I left almost all my graphs at home, but I couldn't resist throwing in just this one, because I'm a geek, and that's how I roll. (Laughter) This is a study that looked at the risk of death over a 14-year period based on four healthy habits: eating enough fruits and vegetables, exercise three times a week, not smoking, and drinking in moderation. 我几乎把我所有的图表放家里了，但我就是无法抗拒想要拿出这张图，因为我是个怪胎，没图表不舒服 。下面我要讲的是一个进行了14年的有关四种健康习惯与死亡风险的研究，吃足够的水果和蔬菜、一个星期锻炼三次、不吸烟、截止饮酒。
Let's start by looking at the normal weight people in the study. The height of the bars is the risk of death, and those zero, one, two, three, four numbers on the horizontal axis are the number of those healthy habits that a given person had. And as you'd expect, the healthier the lifestyle, the less likely people were to die during the study. 我们来看看在研究当中体重正常的人，柱状图的高表示死亡风险，水平坐标上的数字0、1、2、3、4表示一个特定的人拥有健康习惯的个数。跟你们预期的一样，生活习惯越健康，研究中人们死亡的可能性越小。
Now let's look at what happens in overweight people. The ones that had no healthy habits had a higher risk of death. Adding just one healthy habit pulls overweight people back into the normal range. For obese people with no healthy habits, the risk is very high, seven times higher than the healthiest groups in the study. But a healthy lifestyle helps obese people too. 现在我们看看在超重者身上，会发生什么？那些没有任何一个健康习惯的人，有更高的死亡风险 。仅仅增加一个健康的习惯，就会让超重的人回到正常范围。对于那些没有健康习惯的肥胖者，这种风险极高，比那些在研究中最健康的一群人高七倍 。但是健康的生活方式也能帮助肥胖的人。
In fact, if you look only at the group with all four healthy habits, you can see that weight makes very little difference. You can take control of your health by taking control of your lifestyle, even If you can't lose weight and keep it off.事实上，如果你只看有四种健康习惯的组，你会发现体重无关紧要，你可以通过控制生活方式来控制自己的健康，即使你不能减掉体重并且保持住。
Diets don't have very much reliability. Five years after a diet, most people have regained the weight. Forty percent of them have gained even more. If you think about this, the typical outcome of dieting is that you're more likely to gain weight in the long run than to lose it.节食并不是非常值得信赖的，节食五年之后，大多数人体重会反弹，其中百分之四十的人甚至比原来还要重。如果你想到这些节食的一般结果，是在长期过程中更有可能增重而不是减重。
If I've convinced you that dieting might be a problem, the next question is, what do you do about it? And my answer, in a word, is mindfulness. I'm not saying you need to learn to meditate or take up yoga. I'm talking about mindful eating: learning to understand your body's signals so that you eat when you're hungry and stop when you're full, because a lot of weight gain boils down to eating when you're not hungry. How do you do it? 如果我已经让你相信，节食会带来一些麻烦 。下一个问题便是，你会做些什么？我的答案是，简单说，就是留心。我并不是说你需要学着调整或开始练习瑜伽，我指的是在吃上面多加注意，学会了解身体发出的信号，这样可以让你在饿的时候吃，在饱的时候停下来。因为大量的增重归结为：在并不饿的时候吃东西，你该怎么做？
Give yourself permission to eat as much as you want, and then work on figuring out what makes your body feel good. Sit down to regular meals without distractions. Think about how your body feels when you start to eat and when you stop, and let your hunger decide when you should be done. It took about a year for me to learn this, but it's really been worth it. 允许自己尽可能的吃，然后找出吃多少才能让你感觉舒服。你需要一心一意坐下来吃一日三餐，当你开始吃和吃完之后，想想你的身体感觉如何。让你的饥饿感决定，你应该什么时候停止。我花了差不多一年才学到这些，但是我做这些确实很值得。
I am so much more relaxed around food than I have ever been in my life. I often don't think about it. I forget we have chocolate in the house. It's like aliens have taken over my brain. It's just completely different. I should say that this approach to eating probably won't make you lose weight unless you often eat when you're not hungry, but doctors don't know of any approach that makes significant weight loss in a lot of people, and that is why a lot of people are now focusing on preventing weight gain instead of promoting weight loss. 在食物面前，比起之前我变得更加释然。我经常不去想它，我会忘记家里有巧克力，这就像外星人控制了我的大脑一样， 生活变得完全不同了。我需要说的是，这个方法可能不会让你减重，如果你不是经常在你不饿的时候吃东西。但是医生们并不知道可以让很多人都能显著减重的方法，这就是为什么现在很多人专注于防止体重增加，而不是让体重减轻 。
Let's face it: If diets worked, we'd all be thin already. Why do we keep doing the same thing and expecting different results? 我们需要面对现实，如果节食有效的话，所有人现在都已经瘦下来了 。为什么我们一直做同样的事情并且期待不同的结果？
Diets may seem harmless, but they actually do a lot of collateral damage. At worst, they ruin lives: Weight obsession leads to eating disorders,especially in young kids. In the U.S., we have 80 percent of 10-year-old girls say they've been on a diet. Our daughters have learned to measure their worth by the wrong scale. 节食似乎是无害的，但是它确实会带来很多附带的危害。在最坏的情况下，它会危及生命。体重的困扰会导致饮食混乱，特别是在小孩子当中出现。在美国，80%的10岁女孩说她们在节食。我们的女儿们学会的是用错误的标尺来衡量她们的价值。
Even at its best, dieting is a waste of time and energy. It takes willpower which you could be using to help your kids with their homework or to finish that important work project, and because willpower is limited, any strategy that relies on its consistent application is pretty much guaranteed to eventually fail you when your attention moves on to something else.即使结果很好，节食还是既浪费时间又浪费精力，它消耗一种意志，而你可以将其用在帮助你的孩子完成作业或者完成一项重要的计划，因为意志十分有限。任何依赖坚持不懈的行动计划，当你把注意力分散到其他方面的时候，最终一定会以失败告终。
Let me leave you with one last thought. What if we told all those dieting girls that it's okay to eat when they're hungry? What if we taught them to work with their appetite instead of fearing it? I think most of them would be happier and healthier, and as adults, many of them would probably be thinner. I wish someone had told me that back when I was 13.我来让大家做一下最后的思考，假如我们告诉所有那些节食的女孩子们，当她们觉得饿时吃东西是可以的将会怎么样？假如我们教她们控制她们的食欲 而不是惧怕它？我想她们大多数会变得更加快乐健康，当她们成年之后 她们中很多人可能会变瘦，我真希望在我13岁那年有人告诉我这些。
Thanks.谢谢。
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