Dr. Jason Fung

The cleanest experiments we have are really when we give people drugs or take away drugs because it's a single sort of thing.

So if I give somebody insulin, what happens?

Well, they gain weight.

Everybody gains weight as soon as I give them insulin or enough insulin.

It doesn't matter how much you exercise, how much willpower you have, how good or bad your diet is, you will gain weight.

Why?

Because I told your body to gain weight, which means I'm pushing your thermostat up.

If I give people cortisol, I can use a synthetic cortisol called prednisone.

And again, same thing.

I give it to people, they gain weight.

I don't even care how much exercise, willpower, all that stuff, they will gain weight.

That means I've pushed that thermostat up.

If I give GLP-1, if I push the GLP-1 system up high, what happens?

Well, you lose weight, right?

That's Ozempic and Munjarro and so on.

Well, that means you've pushed it down.

How?

You've activated these hormones, right?

The GLP-1 system.

It's not the calories.