Dr. Jason Fung

Oh, absolutely.

The question, so when you think about, so body fat, you think about the energy balance equation, body fat equals calories in minus calories out.

This often leads people to say, well, just eat 500 fewer calories and you'll lose a pound of fat per week.

It's unquestionably false because every single study that we've done over the last 50 years shows that if you eat 500 fewer calories, then over time, depending on what foods you're eating, eventually your body will just burn 500 fewer calories.

So that's your basal metabolic rate, the number of calories that your body is expending in one day.

So we see this in almost every single study.

We've known about it for like 80 years at least.

You eat fewer calories, your body burns fewer calories.

Well, that's going to limit how much weight you're gonna lose, right?

So this idea that just eat fewer calories will automatically lead to weight loss is completely false because we know that eating fewer calories leads also to burning fewer calories

So you eat 500 less, your body burns 500 less, and you're not losing any body weight.

Yeah.

So that's that yo-yo dieting effect.

So say you start with 2,000 calories in, 2,000 calories out.

You're not gaining weight.

You're not losing weight, right?

Now you decide, okay, I'm going to go on a diet.

So you go down to 1,500 calories thinking that you're going to burn 2,000.

and the body fat's gonna provide 500, right?

That's how you balance that equation.