Here’s the scenario: You’re stuffed because you’ve just polished off a large pizza. So, how can you still find room for a bowl of ice cream?

According to a new study from the University of Naples, it boils down to “pleasure eating.” That’s the term researchers use for when we continue to eat even after we’ve taken in all the calories our body needs to survive.

In the study, researchers invited people to eat until they felt full. Then, participants were given two rounds of dessert, including a serving of their favorite food, like ice cream, and a serving of something less-appetizing, but of equal caloric value, like broccoli. Meanwhile, as the participants ate, researchers measured certain chemical levels in their bloodstream.

So what happened? It turns out that when we eat foods we love, so-called “pleasure eating,” the body releases chemicals that trigger a feeling of reward, but when we eat less-appetizing foods, our reward chemical levels stay flat or drop. And that’s a big deal because this study shows that the body’s reward system can override feelings of being “full.”

That’s why experts say pleasure eating is dangerous! Because as you might guess, the foods that stimulate our senses the most tend to be fatty, sugary foods, not broccoli, meaning if you’re not careful, rewarding yourself with a snack after a meal can lead to overeating, and make you pack on the pounds.