A lot of the time people go on crazy fad diets where they eliminate entire sections of the food pyramid. Depriving yourself of the things you enjoy completely will never be healthy. If you wants some pizza, you eat that slice of pizza! If you want a brownie, you enjoy that chocolaty goodness. Just do not go over your own idea of overboard. There is no magical limit for these things, but in the end if you're no longer enjoying eating then, what's the point?
Tip #2 Create a Motivational Wall