I like to compare addiction with hunger. You are feeling bad when you have it and only eating will get you feel comfortable again. Also it is hard to fast. It's difficult to not eat something.
You are most likely not making the decision " I am eating now so my body has something to process" more in the line of "I'm hungry. I don't want to feel hungry, therefore I'm going to eat"
(edit) And you are absolutely able to get yourself sick that way, depending what you eat and how.
You are not gonna get Brie when you add enough goat cheese to grated Parmesan.