Start a "no" streak, like no chocolate or no cookies or no candy. Take it one day at a time. Don't say I will NEVER eat a chocolate again. Just say, I am trying to see how long I can go without it. I can eat one if I want to, I simply choose not to today.
Giving up chocolate has eliminated a large number of "problem foods" and I have lost 15 pounds. Posting the number of days where I can see it all day is a huge motivation, especially when everyone at work knows what it means.