Dr. Jason Fung

If you exercise, during the exercise, you have reduced appetite.

So you have, it's called exercise-induced anorexia.

So in the middle of a basketball game, you don't suddenly go, oh, wow, I'm really hungry, right?

Because your blood is flowing in your muscles and so on.

You're not thinking about the hunger.

So hunger actually goes down during exercise.

But after exercise, we see this rebound.

So we see that people are actually more hungry after exercise.

And if you're hungrier after exercise, it's gonna cause you to tend to gain more weight.

In fact, there's this very interesting study

that was done a few years ago in Harvard where they measured the sort of calorie difference that you get for children in certain activities.

So they said, okay, what if a child is watching TV?

What's the average caloric difference?

And it was like plus 100 calories per hour.

So for every hour of TV,

they're sort of positive 100 calories over time, right?

And that makes sense.

You're just sitting there.

When you look at mild exercise, it's about the same.

It's about positive 100 calories.