Dr. Alia Crum

Ghrelin.

So ghrelin, medical experts call this the hunger hormone.

Okay.

So the hunger hormone is thought to help regulate hunger and metabolism.

Okay.

So when ghrelin levels are high, that signals to your brain, hey, seek out food, right?

And it also slows metabolism until you actually secure and consume that food.

Okay.

And theoretically, it had been assumed that in proportion to the amount of calories you eat...

ghrelin levels will drop.

So if we go out and have a burger and a milkshake and a lot of calories, ghrelin levels will plummet, which signal to the brain, okay, you can stop prioritizing food consumption and rev up the metabolism in the body to burn the food that you just ate.

Now, of course, if we didn't get food or if we only ate a little bit of food, ghrelin levels would drop only slightly, therefore kind of perpetuating those hunger signals and keeping metabolism slow.

Yes.

So if we had just given them the same milkshake at two different time points, and it's the same person, both time points, same milkshake, we would assume that their bodies would respond exactly the same.

Yes, so here's the catch.

So I'm a psychologist, so I like to play around with how does changing what we believe to be true change how our bodies respond?

So in the study, we actually gave them a 350 calorie milkshake

At one point, we told them it was an indulgent milkshake, 620 calories, high fat, high sugar.

This is really the decadence you deserve, right?

We even had on the label, like, decadence you deserve.