At my gym they are holding a contest to see who can make the most improvement in 8 weeks. During this 8 week period you are eating Paleo style. If you don't know what Paleo is please google it. Basically there is no dairy, no grains, no artificial anything. If you can't pick it up and eat it then it's not Paleo.
I am almost done with my first week. I must say that it is very difficult. Everything is fruit, veggies, and protein. This diet totally changes the way you look at food. If you are interested in the diet here is a good link for recipes.