I noticed the substituting almost immediately. My trio of vices was alcohol, cigarettes and coffee. So when I quit alcohol, I almost instantly noticed that I smoked more and drank more coffee. Although the intake didn't lessen, the personal polemic about it did, after some time. This is theory, but I think once the mind calms down about the 'new-found' addiction, it would be easier to decrease the intake of whatever substance, be it caffeine, sugar or hamburgers. Go from 'most destructive' to 'least destructive' and then, when you feel like it, cut some things out completely (things that aren't as threatening as alcohol) ?
Congrats on the 5 months!