Well I think there are two diets now.
One is the core... that works out you have so many points a day to eat and lots of things are free to eat.. and if you exercise you get more points that you can have as food.. but really why... as you want to lose weight don't you.
The second I am not sure on .. but you get less points as the other but I believe all fruit and veg etc are counted in your points and this goes on your weight/age. You are only allowed these points per day and think the things with exercise works the same.