I think it depends on what one's dietary habits were when using.
For example, one of my favorite drunken activities was creating huge, full-course gourmet meals. I loved to eat when I was drinking. They just seemed to naturally go together. Add the thousands of calories that alcohol creates, and the blimp was flying.
Otoh, others eat very little to nothing when drinking, so they gain weight after quitting. This seems to be more common among women, from my observations.