Dr. Jason Fung

It's the hormones that are affecting it.

You don't get to choose your metabolic rate.

Same as you don't get to choose your hunger, right?

So it's not about willpower because you can willfully not eat, but you can't willfully decide to not be hungry.

You can't will yourself to have a higher metabolic rate.

So this is the piece that sort of is missing from this sort of calories in, calories out.

It's a dynamic thing.

And I don't know why people are obsessed with this idea that your metabolic rate, so let's take exercise out of the equation because that's obviously quite variable.

If you look at the metabolic rate, people always assume that it stays the same.

It's like, but every single study we've done tells you it doesn't stay the same.

right, your metabolic rate goes down.

As you lose that weight, your metabolic rate goes down.

They've done these studies on the biggest loser contestants, for example, and some of these people had metabolic rates of 3,000 and 200 calories a day.

And then as they lost that weight, it went down to like 1,600.

So they're eating a lot less, right?

So then they'll be eating 2,000 calories, which is a lot less than they used to eat, right?

Because they used to eat 3,200.

but they're gaining their weight back.

Why?

Because their metabolic rate went down to 1600.