Why dieting doesn't usually work | Sandra Aamodt

翻译人员: Frank Li 校对人员: Jun CHEN

Three and a half years ago,

三年半前

I made one of the best decisions of my life.

我做了人生中最棒的一个决定

As my New Year's resolution,

作为新年的新决心

I gave up dieting, stopped worrying about my weight,

我放弃了节食， 停止了对自己体重的忧虑

and learned to eat mindfully.

我开始谨慎地对待进食

Now I eat whenever I'm hungry,

现在，只要我饿了我就吃

and I've lost 10 pounds.

我甚至还减了10磅 （约为4.55公斤）

This was me at age 13,

这是我13岁时候的样子

when I started my first diet.

那是我开始第一次节食

I look at that picture now, and I think,

现在我看着这张照片，我想

you did not need a diet,

我需要的不是节食

you needed a fashion consult.

而是一名时尚顾问

(Laughter)

（笑声）

But I thought I needed to lose weight,

但当时我认为自己需要减肥

and when I gained it back,

当我体重反弹回来的时候

of course I blamed myself.

我感到自责

And for the next three decades,

在接下来的三十年里

I was on and off various diets.

我开始又结束了各式各样的节食

No matter what I tried,

无论我采取怎样的努力

the weight I'd lost always came back.

我减去的体重总会反弹回来

I'm sure many of you know the feeling.

我确信你们中的很多人能体会到这感觉

As a neuroscientist,

作为一名神经科学家

I wondered, why is this so hard?

我很疑惑，为什么这如此困难？

Obviously, how much you weigh depends on

很显然，你的重量决定于

how much you eat and how much energy you burn.

你吃了多少和你消耗了多少能量

What most people don't realize

但绝大部分人没有意识到的是

is that hunger and energy use

饥饿和消耗

are controlled by the brain,

是由大脑掌控的

mostly without your awareness.

大多数情况下你甚至不会意识到

Your brain does a lot of its work behind the scenes,

你的大脑在后台做了很多事

and that is a good thing,

这很好

because your conscious mind --

因为你的意识

how do we put this politely? --

让我想个更有礼貌的说法---

it's easily distracted.

很容易被分散

It's good that you don't have to remember to breathe

当你专注于电影的时候

when you get caught up in a movie.

你不需要记得呼吸 亦可自由畅快地呼吸

You don't forget how to walk

你不会因为思考晚餐吃什么

because you're thinking about what to have for dinner.

而忘记如何行走

Your brain also has its own sense

你的大脑对于你的体重

of what you should weigh,

有着自己的一套想法

no matter what you consciously believe.

无论你有意识地在想些什么

This is called your set point,

这被叫做你的设定值

but that's a misleading term,

但那是个误导人的术语

because it's actually a range

因为事实上它是一个范围

of about 10 or 15 pounds.

大约在10到15磅内浮动

You can use lifestyle choices to move your weight

你可以通过选择生活方式来改变你的体重

up and down within that range,

在这个范围内上下浮动

but it's much, much harder to stay outside of it.

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

大脑的一个部分叫下丘脑

that regulates body weight,

它调节着你的体重

there are more than a dozen chemical signals

你的大脑有十多种化学信号

in the brain that tell your body to gain weight,

会告诉你的身体去增加体重

more than another dozen that tell your body to lose it,

还有另外十多种信号会告诉你的身体去减重，

and the system works like a thermostat,

这系统的工作原理就像恒温器

responding to signals from the body

对身体接收到的信号做出反应

by adjusting hunger, activity and metabolism,

通过调节饥饿感，活动，新陈代谢

to keep your weight stable as conditions change.

根据条件的变化，维持你的体重

That's what a thermostat does, right?

这就是恒温器的作用，对吧？

It keeps the temperature in your house the same

恒温器会根据房屋外部天气的变化不断调节

as the weather changes outside.

从而保持室内的温度恒定

Now you can try to change the temperature

现在你可以通过在冬季打开一扇窗

in your house by opening a window in the winter,

来调节室内的温度

but that's not going to change the setting on the thermostat,

但这个动作并不会改变恒温器的设置

which will respond by kicking on the furnace

恒温器对此的反应是打开火炉

to warm the place back up.

把屋内的温度调节回温暖的状态

Your brain works exactly the same way,

你的大脑就是这样工作的

responding to weight loss by using powerful tools

当你体重减轻的时候

to push your body back

它会用有效地工具让你的体重回归

to what it considers normal.

回归到它认为正常的状态

If you lose a lot of weight,

如果你减重过多

your brain reacts as if you were starving,

你大脑的反应就是你快饿死了

and whether you started out fat or thin,

无论你最初是胖还是瘦

your brain's response is exactly the same.

大脑的反应都是一模一样的

We would love to think that your brain could tell

我们非常希望我们的大脑可以

whether you need to lose weight or not,

感知我们是否需要减重

but it can't.

但它不能

If you do lose a lot of weight,

如果你真的减去了很多体重

you become hungry,

你会感到很饿

and your muscles burn less energy.

你的肌肉会消耗更少的能量

Dr. Rudy Leibel of Columbia University

哥伦比亚大学的鲁迪利贝尔博士

has found that people who have lost

发现那些

10 percent of their body weight

减去体重10%的人们

burn 250 to 400 calories less

消耗的热量比未减重之前少250到400卡路里

because their metabolism is suppressed.

因为他们的新陈代谢被抑制了

That's a lot of food.

这些（热量）等于相当多的食物中所含的热量

This means that a successful dieter

这意味着一个成功的节食者

must eat this much less forever

必须比和他相同体重的人

than someone of the same weight

少吃这么多食物

who has always been thin.

因为这个人一直都这么瘦

From an evolutionary perspective,

从进化的角度上讲

your body's resistance to weight loss makes sense.

人的身体对于减重的抵制情有可原

When food was scarce, our ancestors' survival

当食物匮乏时，我们的祖先

depended on conserving energy,

依靠身体中储存的能量生存

and regaining the weight when food was available

当食物充足时增加体重

would have protected them against the next shortage.

将会确保他们在下一次 食物短缺的情况下能够生存下来

Over the course of human history,

在人类历史进程中

starvation has been a much bigger problem

饥饿一直是比吃撑

than overeating.

更大的问题

This may explain a very sad fact:

这说明了一个非常可悲的事实

Set points can go up,

设定值可以增加

but they rarely go down.

但几乎不会减少

Now, if your mother ever mentioned

现在如果你妈妈跟你说

that life is not fair,

生活很不公平

this is the kind of thing she was talking about.

这就是她所说的情形

(Laughter)

（笑声）

Successful dieting doesn't lower your set point.

节食成功并不会降低设定值

Even after you've kept the weight off

即便是你已经减轻体重

for as long as seven years,

长达七年之久

your brain keeps trying to make you gain it back.

你的大脑一直会让你把减掉的体重增回来

If that weight loss had been due to a long famine,

如果减重是由长时间饥饿造成的

that would be a sensible response.

这是合情合理的反应

In our modern world of drive-thru burgers,

在充斥着得来速汉堡的现代世界

it's not working out so well for many of us.

这种反应并不适用于大多数人

That difference between our ancestral past

过去我们祖先的生活

and our abundant present

和现代人富足的生活的差异

is the reason that Dr. Yoni Freedhoff

是渥太华大学的

of the University of Ottawa

约尼 弗雷德霍夫 博士

would like to take some of his patients back to a time

想让他的一些病人回到

when food was less available,

食物不充足年代的原因

and it's also the reason

这也是为什么

that changing the food environment

改变饮食环境

is really going to be the most effective solution

将成为解决肥胖问题

to obesity.

最有效的方法

Sadly, a temporary weight gain

不幸的是，短暂的增重

can become permanent.

可变为永久的增重

If you stay at a high weight for too long,

如果你长时间处于超重状态

probably a matter of years for most of us,

对于我们大多数人来说可能是若干年

your brain may decide that that's the new normal.

你的大脑就会觉得这是新的正常状态

Psychologists classify eaters into two groups,

心理学家把“吃货”分成两类

those who rely on their hunger

一类人靠本能的饥饿反应去吃

and those who try to control their eating

另一类人则是用意志去控制饮食

through willpower, like most dieters.

就像大多数节食者一样

Let's call them intuitive eaters and controlled eaters.

我们称他们为本能型食着和自控型食者

The interesting thing is that intuitive eaters

有趣的是本型能食者

are less likely to be overweight,

很少会超重

and they spend less time thinking about food.

并且他们会花较少的时间思考吃什么东西

Controlled eaters are more vulnerable

自控型食者则更容易受到

to overeating in response to advertising,

广告，超大分量和自助餐的影响

super-sizing, and the all-you-can-eat buffet.

而造成饮食过量

And a small indulgence,

一个小小的放纵

like eating one scoop of ice cream,

比如一勺冰激凌

is more likely to lead to a food binge

更有可能在自控型食者中

in controlled eaters.

导致暴饮暴食的结果

Children are especially vulnerable

在这种节食和暴饮暴食的循环下

to this cycle of dieting and then binging.

孩子们特别容易受到伤害

Several long-term studies have shown

一些长期研究表明

that girls who diet in their early teenage years

在青少年初期节食的女孩

are three times more likely to become overweight

在五年之后超重的可能性

five years later,

是未节食者的三倍

even if they started at a normal weight,

即便她们一开始体重正常

and all of these studies found

所有这些研究发现

that the same factors

预示体重增加

that predicted weight gain

的因素

also predicted the development of eating disorders.

也预示着饮食失调的产生

The other factor, by the way,

顺便说一下

those of you who are parents,

请家长们注意了

was being teased by family members

另外一个因素

about their weight.

是“因体重而被家庭成员取笑”

So don't do that.

所以别那样做

(Laughter)

（笑声）

I left almost all my graphs at home,

我几乎把我所有的图表放家里了

but I couldn't resist throwing in just this one,

但我就是无法抗拒想要拿出这张图

because I'm a geek, and that's how I roll.

因为我是个书虫，没图表不舒服

(Laughter)

（笑声）

This is a study that looked at the risk of death

下面我要讲的是一个进行了14年的

over a 14-year period

有关四种健康习惯

based on four healthy habits:

与死亡风险的研究

eating enough fruits and vegetables,

吃足够的水果和蔬菜

exercise three times a week,

一个星期锻炼三次

not smoking,

不吸烟

and drinking in moderation.

饮酒节制

Let's start by looking at the normal weight

我们来看看在研究当中

people in the study.

体重正常的人

The height of the bars is the risk of death,

柱状图的高表示死亡风险

and those zero, one, two, three, four numbers

水平坐标上的

on the horizontal axis

数字0、1、2、3、4

are the number of those healthy habits

表示一个特定的人

that a given person had.

拥有健康习惯的个数

And as you'd expect, the healthier the lifestyle,

你们的预期是，生活习惯越健康

the less likely people were to die during the study.

研究中人们死亡的可能性越小

Now let's look at what happens

现在我们看看在超重者身上

in overweight people.

会发生什么

The ones that had no healthy habits

那些没有任何一个健康习惯的人

had a higher risk of death.

有更高的死亡风险

Adding just one healthy habit

仅仅增加一个健康的习惯

pulls overweight people back into the normal range.

就会让超重的人回到正常范围

For obese people with no healthy habits,

对于那些没有健康习惯的肥胖者

the risk is very high, seven times higher

这种风险极高，比那些在研究中

than the healthiest groups in the study.

最健康的一群人高七倍

But a healthy lifestyle helps obese people too.

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

事实上，如果你只看

with all four healthy habits,

有四种健康习惯的组

you can see that weight makes very little difference.

你会发现体重无关紧要

You can take control of your health

你可以通过控制生活方式

by taking control of your lifestyle,

来控制自己的健康

even If you can't lose weight

即使你不能减掉体重

and keep it off.

并且保持住

Diets don't have very much reliability.

节食并不是非常值得信赖的

Five years after a diet,

节食五年之后

most people have regained the weight.

大多数人体重会反弹

Forty percent of them have gained even more.

其中百分之四十的人甚至比原来还要重

If you think about this,

如果你想到这些

the typical outcome of dieting

节食的一般结果

is that you're more likely to gain weight

是在长期过程中更有可能增重

in the long run than to lose it.

而不是减重

If I've convinced you that dieting

如果我已经让你相信

might be a problem,

节食会带来一些麻烦

the next question is, what do you do about it?

下一个问题便是，你会做些什么？

And my answer, in a word, is mindfulness.

我的答案是，简单说，就是留心

I'm not saying you need to learn to meditate

我并不是说你需要学着调整

or take up yoga.

或开始练习瑜伽

I'm talking about mindful eating:

我指的是在吃上面多加注意

learning to understand your body's signals

学会了解身体发出的信号

so that you eat when you're hungry

这样可以让你在饿的时候吃

and stop when you're full,

在饱的时候停下来

because a lot of weight gain boils down

因为大量的增重归结为

to eating when you're not hungry.

在并不饿的时候吃东西

How do you do it?

你该怎么做？

Give yourself permission to eat

允许自己尽可能的吃

as much as you want, and then work on figuring out

然后找出

what makes your body feel good.

吃多少才能让你感觉舒服

Sit down to regular meals without distractions.

你需要一心一意坐下来吃一日三餐

Think about how your body feels

当你开始吃和吃完之后

when you start to eat and when you stop,

想想你的身体感觉如何

and let your hunger decide

让你的饥饿感决定

when you should be done.

你应该什么时候停止

It took about a year for me to learn this,

我花了差不多一年才学到这些

but it's really been worth it.

但是我做这些确实很值得

I am so much more relaxed around food

在食物面前，比起之前

than I have ever been in my life.

我变得更加释然

I often don't think about it.

我经常不去想它

I forget we have chocolate in the house.

我会忘记家里有巧克力

It's like aliens have taken over my brain.

这就像外星人控制了我的大脑一样

It's just completely different.

生活变得完全不同了

I should say that

我需要说的是

this approach to eating probably won't make you lose weight

这个方法可能不会让你减重

unless you often eat when you're not hungry,

如果你不是经常在你不饿的时候吃东西

but doctors don't know of any approach

但是医生们并不知道可以让很多人

that makes significant weight loss in a lot of people,

都能显著减重的方法

and that is why a lot of people are now focusing on

这就是为什么现在很多人专注于

preventing weight gain

防止体重增加

instead of promoting weight loss.

而不是让体重减轻

Let's face it:

我们需要面对现实

If diets worked, we'd all be thin already.

如果节食有效的话，所有人现在都已经瘦下来了

(Laughter)

（笑声）

Why do we keep doing the same thing

为什么我们一直做同样的事情

and expecting different results?

并且期待不同的结果？

Diets may seem harmless,

节食似乎是无害的

but they actually do a lot of collateral damage.

但是它确实会带来很多附带的危害

At worst, they ruin lives:

在最坏的情况下，它会危及生命

Weight obsession leads to eating disorders,

体重的困扰会导致饮食混乱

especially in young kids.

特别是在小孩子当中出现

In the U.S., we have 80 percent of 10-year-old girls

在美国，80%的10岁女孩

say they've been on a diet.

说她们在节食

Our daughters have learned to measure their worth

我们的女儿们学会的是用错误的标尺

by the wrong scale.

来衡量她们的价值

Even at its best,

即使结果很好

dieting is a waste of time and energy.

节食还是既浪费时间又浪费精力

It takes willpower which you could be using

它消耗一种意志，而你可以将其用在

to help your kids with their homework

帮助你的孩子完成作业

or to finish that important work project,

或者完成一项重要的计划

and because willpower is limited,

因为意志十分有限

any strategy that relies on its consistent application

任何依赖坚持不懈的行动计划

is pretty much guaranteed

当你把注意力分散到其他方面的时候

to eventually fail you

当你把注意力分散到其他方面的时候

when your attention moves on to something else.

最终一定会以失败告终

Let me leave you with one last thought.

我来让大家做一下最后的思考

What if we told all those dieting girls

假如我们告诉所有那些节食的女孩子们

that it's okay to eat when they're hungry?

当她们觉得饿时吃东西是可以的将会怎么样？

What if we taught them to work with their appetite

假如我们教她们控制她们的食欲

instead of fearing it?

而不是惧怕它？

I think most of them would be happier and healthier,

我想她们大多数会变得更加快乐健康

and as adults,

当她们成年之后

many of them would probably be thinner.

她们中很多人可能会变瘦

I wish someone had told me that

我真希望在我13岁那年

back when I was 13.

有人告诉我这些

Thanks.

谢谢

(Applause)

（鼓掌）