It's TED Talks Daily. I'm Elise Hugh.

We're about to hear a really fascinating talk about obesity from researcher Mott's Tong Christensen.

Not only does he break down the research that shows in a lot of ways our weight is predetermined,

he also lays out an audacious goal to prevent and even cure obesity.

Have you ever wondered why a pair of siblings living in the same house with the same parents,

with the same food, sometimes up in opposite side of the weight spectrum.

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

much we eat. And probably more importantly, I've been studying how eat our unique bodies

respond differently to the same food and the same

environment. To be more precise, I study obesity. During my training as an MD PhD, I was very

fascinated by a serious experiment done by Barry Levin. He took 100 rats and subjected them to high-fat feeding.

After months of feeding, he ended up with a bell-shaved curve and a weight distribution

with some skinny rats and some obese rats and some in the middle. 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.

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

And here's the really interesting part.

Then he took the skinny, all the obese,

and either massively over or underfed them. And their weight would of course go up and down depending on the weight dietary regimen. But it was as if their little bodies would remember

the same old weight trajectory.

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

It was like as if you could dress up the obese rat in a skinny sheep's clothing, but the obese rat nature was still scratching to get out.

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