CAD (Carbohydrate Addict's Diet) is the original diet book written by Dr's Richard and Rachael Heller. They later wrote an updated book, CALP (I think that stands for Carbohydrate Addicts Life Plan) which added some extra information. The essential programs are the same. CALP gave some other options, things like curbing use of sweetners, taking chromium, etc to help with the program. The Hellers have since written other books as well, but the basic program hasn't really changed.