饮食变迁（2010）

our hunter-gatherer ancestors
我们以采集狩猎为生的祖先
had to live off whatever they could find.
必须靠食用他们能找到的东西为生
Sometimes that wasn't much.
有时那些是不够的
Which is when fat as an
也就是说 脂肪作为
efficient storage system really came into its own.
有效的储存系统 应该得到应有的重视
Populations went through periods of feast and famine.
人们会经历食物充足以及饥荒的时期
During the periods of famine,
在饥荒的时期
maybe two-thirds or
或许三分之二甚至
three-quarters of the population would disappear.
四分之三的人口会死于饥荒
But those who were chubbier
而那些丰满的人
or those fatter babies would survive and then
或者说是肥胖的婴儿则会活下来
procreate themselves and pass on these genes.
繁衍后代 将自己的基因传递下去
So, according to this theory,
根据这一理论
at times of famine it was
饥荒的时期
literally a case of the survival of the fattest.
实际上是胖者生存的时期
The cycles of feast and famine
在饥饿与富足的循环中
that humankind has been
人类则要经历
subjected to was an important natural selective
重要的自然选择过程
process, in which all the
在这一过程中
babies or the people a little bit chubbier
丰满的成人或者是婴儿
would survive the periods of famine and
可以在饥荒的情况下生存下来
then be able to gain the weight during the period of feast.
而在食物充足的时候 他们会增加体重
This could explain why large parts of the
这就可以解释 为什么大多数人
population have a tendency to lay down fat stores easily.
都有易于储存脂肪的倾向
It's only very recently in
这是个在人类历史上
human history that this has become a problem.
近期才显露的问题
Now, the feast is constant.
现在 食物充足才是常态
You have food available every corner,
我们随处都可以找到食物
very cheap, very palatable,
价格不贵而且美味可口
and this is really a perfect mixture
综合以上情况
to provide the expression of these
那些基因就会表现为
genes and confer obesity and weight gain to these people.
人们的肥胖以及体重增加
So if evolution was selecting for fatness,
如果说肥胖是进化的选择
the question remained as
那么依然存在一个问题
to what was compelling those individuals to put on the pounds.
是什么在迫使着人们增加体重
Scientists suddenly clocked that maybe what they should
科学家忽然注意到 也许他们应该
be looking at was what was
关注究竟是什么
driving us to eat so much - our appetite.
在促使我们不断进食 即我们的食欲
Proving its importance was a different matter.
证明它的重要性则是另外一回事
But what followed was a
接下来要说的
complex tale of scientific detective work,
是一个复杂的科学探索工作故事
involving a German boy with
这其中包括一个
an unusual brain condition and a fat mouse.
大脑与众不同的德国男孩 和一只肥老鼠
The idea that there's an evolutionary-based,
生物渴望食物是基于进化本能
biological drive to eat is clearly an interesting idea.
是有生物性驱力的 这是个有趣的设想
But until recently, it just remained that, just an idea.
不过在不久之前 这还仅仅是一个设想
Most people believed that our appetites were controlled
大多数人都相信 我们的食欲是完全被
entirely by willpower and voluntary action.
毅力和自主行为控制着的
We've discovered in the last few
我们近几年才发现
years that our brains are actually hard-wired to eat.
我们的大脑对食物有着根深蒂固的渴望
28-year-old Sven's life is dominated by the drive to eat.
28岁的斯文的生活 被进食的欲望控制着
He could literally eat himself to death.
他甚至真的能够把自己吃得撑死
It's not a question of willpower or choice.
这并不是一个有关毅力或者选择的问题
No matter how much food he consumes, he always feels hungry.
不论吃多少东西 他总是感到饥饿
For doctors, Sven demonstrates that
对于医生来说 斯文的个案说明
there is some sort of
有一种能够
hard-wired switch which turns a hunger on or off
控制饥饿的固定转换机制
and his had to be faulty.
而他的机制一定出了问题
But Sven wasn't always like this.
然而斯文并不是一向如此
Until he was seven, his appetite was completely normal.
七岁以前 他的食欲都与常人无异
Then he had an operation to remove a brain tumour.
之后他接受了一个脑肿瘤摘除手术
From that day on, he ate and ate.
从那天开始 他便不停地进食
Sven is only this slim
斯文保持如此的身材
because of enormous efforts
是因为他的家庭与医生
on the part of his family and his doctor.
付出了巨大的努力
What happened was that the operation to remove the tumour
肿瘤摘除手术
somehow damaged his hypothalamus,
伤害到了他的下丘脑
an important nerve centre in the brain.
一个大脑中重要的神经中枢
Damage to his hypothalamus is
他的饮食习惯
what changed his eating behaviour.
因下丘脑的破坏而改变
Actually, we know that patients who have this tumour,
实际上 有这种肿瘤的病人
they don't die because of the tumour.
通常不会死于这种肿瘤
Most of them die because of the overweight that they develop.
而是死于由此引发的肥胖问题
Something in Sven's hypothalamus had to be keeping him hungry.
斯文下丘脑中的某些物质让他一直饥饿
Scientists knew that the hypothalamus
科学家知道 下丘脑
was involved in switching the appetite on and off.
与调控食欲有关
But decades of research had
但是几十年的研究并没有
brought them no closer to knowing exactly how.
让他们得知具体的调节原理
Then along came a big fat clue.
接下来的事 为此提供了重要线索
From the day it was born, this mouse had never stopped eating.
从出生那天起 这只老鼠从未停止进食
Researchers spent ten years
科学家花了十年的时间来
comparing this mutant mouse with other thin mice.
将这只基因突变的老鼠和其它瘦老鼠对比
And unexpectedly, they found
出乎意料地 他们在
the answer in the fat cells of the thin mouse.
瘦老鼠的脂肪细胞中找到了答案
Scientists already knew that if we overate
科学家已经知道 如果我们吃得太多
fat cells blow up like balloons
脂肪细胞就会像气球一样膨胀
to hold more and more fat.
从而容纳更多脂肪
But to their surprise, the research team found that the fat cells
让他们感到惊讶的是 研究小组发现
were also manufacturing
脂肪细胞也会产生一种
a hitherto unknown hormone, leptin.
迄今为止从未发现过的激素 瘦蛋白
To find out that the fat cell was itself producing a hormone
对于脂肪细胞自身可以产生激素
and actually actively participating
并且积极地参与到互相连通的
in a communication network was again revolutionary.
脂肪网络当中的发现是一项革命性的进展
It's changed the way we view fat tissue ever since.
它改变了我们看待脂肪组织的方式
It's not as dumb as we thought.
它并非如我们想象般迟钝
A dumb cell was turning out to be a smart storage system.
迟钝的细胞意外地成为了活跃的储存系统
The fat cells of the thin mice were manufacturing lots of leptin.
瘦老鼠的脂肪细胞产生了大量的瘦蛋白
The researchers quickly discovered
研究人员很快发现
that the obese mouse had none.
肥胖老鼠体内没有任何瘦蛋白
So researchers gave the fat
研究人员向胖老鼠体内注入了
mouse leptin to see if it would stop eating.
瘦蛋白 观察其是否能够停止进食
The results were profound. The
研究的结果具有重要的意义
mice lost 40% of their weight after just four weeks.
老鼠仅四周就减掉了百分之四十的重量
What goes through my mind
我所想到的是
is that maybe we've got our first handle
也许我们第一次有了
on understanding what the molecules are
对控制身体重量的
that control body weight,
分子的理解
and the hairs on the back of my neck stood on end.
我的头发都激动得竖了起来
It was wonderfully exciting.
这太令人激动了
The news that leptin made fat mice
瘦蛋白让胖老鼠在几周内瘦下来的新闻
thin in a matter of weeks had a massive popular appeal.
在广大人群中引起了轰动
Researchers then looked at humans and discovered
研究人员随后对人类进行了研究并发现
that the hormone leptin was a messenger molecule for us, too.
瘦蛋白激素对于我们也是一种信使分子
It travels up to the appetite
它能够到达大脑中
control centre in the brain, the hypothalamus.
控制食欲的神经中枢 下丘脑
The hypothalamus acts like a thermostat.
下丘脑像自动恒温器一样工作
So if body fat increases,
如果体内脂肪增加
the leptin increases and appetite goes down.
瘦蛋白增加 食欲下降
When we lose fat,
如果脂肪减少
leptin signals become weaker and we eat.
瘦蛋白信♥号♥♥减弱 我们摄取食物
It's very clear now that there are several biological mechanisms
我们十分清楚 有数种生理机制
that determine how much
可以决定个体的体内
fat each individual maintains in their body,
需要保存多少脂肪
and any change, either by gaining
任何变化 无论是体重增加
weight or losing weight, is actively resisted.
或是体重减少 都可以得到有效地抑制
This is true for people who are
这对于略微超重
mildly overweight or people that are grossly obese.
或者是严重肥胖的人都是成立的
Cathy looks just great in hand-dyed,
凯西穿着这件手工染制的
original button-down front
纽扣领口设计的
in a full circle dress.
服饰看起来很好看