The best way to do CD is just to have water, and black tea and coffe if you really need it.
Diet drinks may kick you out of the fat burning process, but also may give you cravings, citric acid is in most diet drinks and gives major cravings.
When well established into the diet then the ZERO drinks can be had in moderation, ie 1 small glass per day is what CD say, however again this may cause pysychological (sp?) hunger, and I know for me it wasnt worth it.
Also I thought what on earth do they put in these drinks to make them zero everything!!!!!!!!!!!
Its a personal choice, for some a small glass of zero drink (zero coke or doc pepper etc) is what they have as a treat, however, water is the key x x