Anyone who has ever tried to go without sugar or treats can probably tell you... it doesn't last very long. And if you fall off the dessert wagon, it can be a rough landing. Here's an idea to try.
Within your daily budget (caloric budget) allot 100-200 calories at the end of the day for your favorite treat. (chocolate!!) but there's a catch. If you blow your budget by the end of the day, and don't have enough calories left in your bank... no treat for you. Reward yourself for sticking to your goals and calorie count. And you are having just the right sized portion too.
Sometimes, this is what helps me resist the chips or the extra big lunch -- knowing that at the end of the day, I have a favorite goodie waiting for me.