Hi,
I was addicted to carbs, sugar, and chocolate. I had to "step" down from the bad foods gradually. I started with replacing all my white carbs for wheat ones: wheat pasta, wheat bread, brown rice, quinoa. I found some low calorie, low fat dark chocolate substitutes for my chocolate/ sugar cravings.
I try to keep my frig/pantry stocked with better choices - apples, bananas, greek yogurt, quinoa or couscous mixed with sauteed vegetables for a quick lunch/snack.
I couldn't just cut the carbs out. I had to keep them in and gradually remove them. Otherwise, I found myself cheating late-night and sabotaging myself.
I make cauliflower mashed potatoes and baked sweet potato french fries (because sometimes you just can't shake the french fry craving!)
I drink a large glass of milk and water before I go out, and I always start with a salad at a party (or veggies if they don't have salad). And I will allow myself to have 1 bite of dessert. For alcohol, I try to stick to diet coke/tonic/soda water mixers or a glass of wine. I stay away from the really sugary and creamy alcoholic beverages.
And most importantly, I don't beat myself up if I cave in to temptation. I just make sure I bring it extra hard when I workout the next day

good luck,
Rachael