Easier said than done, I know, but the thing I find helps most people is to understand that you can't refrain from doing something you like. You can, however, change the person you are into the kind of person who doesn't even like that stuff. Sugar Smacks still taste the same as they did under Carter, but I don't know anybody who still eats them. Do the same for soda.
In medical school a lot of the guys (who went into ortho) went to the gym and would discuss with euphoria how much canned tuna they ate. "There's 15g of protein and zero fat!" they'd whisper to each other, and they'd sooner eat salamander eyes than lick a Dorito. That was the
kind of guys they were.
This may not be a reassuring solution to some, but I can promise you that it is the only solution: you have to decide you're not the kind of person who wastes time on that. Condemning it, banning it, hiding from it-- all will lead to failure.
http://thelastpsychiatrist.com/2011/02/hes_just_not_that_into_anyone.html