Have you ever wondered why a pair of siblings living in the same house with the same parents, with the same food, sometimes end up in opposite sides of the weight spectrum?

你是否想过为什么一对兄弟姐妹生活在同一屋檐下，有一样的父母，吃一样的食物，有时他们的体重却截然不同？

My name is Mads and for the last 25 years, I've been studying what we eat, when we eat and how much we eat.

我叫麦斯，在过去的25年里，我一直在研究我们吃的是什么，什么时候吃，以及吃多少的问题。

And probably more importantly, I've been studying how each of our unique bodies responds differently to the same food and the same environment.

更重要的是，我也一直在研究我们每个独特的身体，在相同环境下对同一种食物的不同反应。

To be more precise, I study obesity.

更准确的说，我研究肥胖问题。

During my training as an MD, PhD, I was very fascinated by a series of experiments done by Barry Levin.

在我作为医学生博士培训期间，我对巴里·莱文所做的一系列实验感到非常着迷。

He took 100 rats and subjected them to high-fat feeding.

他给一百只老鼠喂高脂肪的食物。

After months of feeding, he ended up with a bell-shaped curve and a weight distribution with some skinny rats and some obese rats and some in the middle.

经过一个月的喂养，他最终获得一个有关体型的权重分布和钟型曲线，这个结果里包含一些瘦老鼠，一些胖老鼠和一些肥瘦居中的老鼠。

What he then did was to take the skinny rats and breed them among themselves, and the heavy rats, and he bred those among themselves.

接下来，他选出瘦老鼠，让他们自己繁殖。同时，他也让胖老鼠成群一起繁殖。

And after rounds of breeding, he ended up with two distinct populations: a diet-resistant rat and an obesity-prone rat.

经过几轮繁殖，他最终得到了两个不同的种群：一种不易肥胖的老鼠，和一种极易肥胖的老鼠。

And here's the really interesting part.

有趣的是，

Then he took the skinny or the obese, and either massively over- or underfed them.

他接着给瘦老鼠和胖老鼠，或是过度喂食或者少量喂食。

And their weight would, of course, go up and down depending on the dietary regimen.

当然老鼠的体重会按照不同的喂食方式增加或者减少。

But it was as if the little bodies would remember the same old weight trajectory.

但是就像这个小小的身体会记住他们以前的体重一样，

So once the dietary regimen was stopped, the rats went right back to the initial weight trajectory.

一旦停止喂食方案，老鼠就会回到他们的初始体重。

It was like as if you could dress up the obese rat in a skinny sheep's clothing.

就好像你把一只肥胖的老鼠放进了瘦老鼠的衣服里。

But the obese rat nature was still scratching to get out.

胖老鼠还是会自然的想要挣脱出来。

The same thing applies to humans.

同样的事情放到人类上，

If you take a thousand kids and weigh them, their weight will also be distributed in a bell-shaped curve.

如果你去选一千个孩子称体重，他们的体重也会呈现出一个钟型曲线。

Some skinny, some in the middle and some heavy.

有些孩子体型偏瘦，有些不胖不瘦，又有些偏胖。

We know that some of the skinny kids will remain skinny throughout life, and some of the obese kids will stay obese throughout life.

我们知道有些瘦孩子一生都会保持苗条，一些胖孩子一生都有可能会保持肥胖。

You could argue that their weight, to some degree, has been predetermined.

从某种程度上说，你可以认为，他们的体重已经被预先决定了。

You could also argue that obesity is a disease.

你也可以说肥胖就是一种疾病。

Wait, did I just say that obesity a disease? Yes.

等下，我刚刚是不是说肥胖是一种疾病？是的。

There's actually data and science that shows that.

确实有一些数据和科学表明这个观点。

And I've made it my audacious life goal to come up with a solution to prevent, treat or even cure obesity.

我也已经把想出一个可以预防、治疗、甚至是治愈肥胖症的办法大胆地作为我的终生目标。

Let me explain.

让我来解释一下，

In the early 1980s and 1990s, obesity was considered a potential global problem, a global problem of a magnitude that led WHO in the end of 1990s to declare obesity a global pandemic.

在1980年代和1990年代初期，肥胖被认为是潜在的全球问题，一个巨大的全球问题，这个问题让世卫组织在1990年代后期宣布肥胖是一个全球大流行病。

And I probably don't have to tell you why.

我可能不需要告诉你为什么。

Higher rates of diabetes, hypertension, cardiovascular disease, even some cancers, osteoarthritis and a clear link to mental conditions such as depression.

大量的糖尿病，高血压，心血管疾病，甚至是一些癌症和骨关节炎，以及与抑郁等精神状况的明确联系。

So as the number of obese individuals grew, so did the number of people suffering from these diseases.

所以随着肥胖人数的增加，受这些疾病困扰的人数也在增加。

Today, more than 50 percent of the US adult population are living with obesity or overweight.

如今，有超过百分之五十的美国成年人正处于肥胖和超重的情况。

From a health perspective, that is devastating.

从健康的角度看，这个数据是毁灭性的。

But it's not only a US problem.

然而，这并不仅仅是美国存在的问题。

The obesity surge has made obesity a global health problem.

肥胖潮已经成为了全球的健康问题。

Many inside and outside the medical community believe obesity is not a disease.

许多医学界内外的机构相信肥胖并不是疾病。

They believe that obesity is a condition, a condition brought about by too much eating and too little exercise.

他们相信肥胖只是一种状况，一种吃太多和缺少锻炼的状况。

As a matter of fact, a lot of people living with obesity think that too.

事实上，很多肥胖的人也同样这么认为。

They believe that their weight is 100 percent their own fault, which can lead to self-blame and low self-esteem, and perhaps even shame or stress eating, which is both heartbreaking, as well as counterproductive.

他们相信他们的超重完全都是他们自己的错误，这样的想法会导致他们自责并且没有自信，甚至会引起羞愧和压力下暴食，这既令人心碎，又会适得其反。

But where is the scientific proof that obesity is a disease?

但关于肥胖是一种病的科学证明在哪里？

Well, medically speaking, there's many ways to define disease, but let me give you just three examples.

从医学上说，有很多种方式可以定义疾病，但是让我和你说三个例子，

As a process that impairs your functionality and reduces life expectancy — obesity, check.

第一，疾病是一个损害你身体的功能和减少寿命的过程——肥胖，就是会这样！

You can define disease as a process that leaves you more susceptible to other diseases or causes disease. Obesity, check.

你可以把疾病定义为一个让你有更大的机会患上别的疾病的过程。肥胖，就是会这样！

Or you can define disease as a genetic impairment that leads to functional impairment, like, for instance, a duplication of genes on chromosomes.

又或者你可以定义疾病为一种遗传缺陷，从而导致身体机能缺陷。比如说，染色体上基因的重复。

There is clear evidence that a single gene mutation can lead to obesity, such as, for instance, leptin deficiency and POMC deficiency.

有明确的证据表明，单一基因的突变会导致肥胖，例如瘦素和阿黑皮素原的缺陷。

We also have two-three genes leading to obesity.

我们也有二至三个基因导致肥胖。

And it's my prediction that we, by the year 2030, will be able to explain most obesity by the genetic makeup of the individual.

我预计在2030年的时候，我们可以用个体的基因组成来解释大部分的肥胖问题。

So obesity as a disease by this measure, check.

所以通过这个方法验证，肥胖确实是一种疾病。