There’s a reason it takes every last bit of willpower not to eat that fifth slice of pizza — while it takes approximately zero discipline not to eat that fifth whole cucumber.

A new study out of the University of Michigan figured out which foods are the most and least addictive.

The ten most addictive foods are: Pizza, chocolate, chips, cookies, ice cream, French fries, cheeseburgers, soda, cake and cheese.

The ten least addictive are: Cucumbers, carrots, beans, apples, brown rice, broccoli, bananas, salmon, corn and strawberries.

The researchers say almost all of the most addictive foods have two things in common: They’re processed and they’re high in fat.

They say pizza is number one because of a protein in the milk called casein. When the casein breaks down in your system, it can actually trigger the same parts of your brain as drugs.