I start the fast Monday
They probably told you that because red dye #? is supposed to be toxic. Maryellen, the Bariatric Coordinator at St Francis Hospital told me the number but I forget what it is. (She's an RN as well.) Anyway, it doesn't have anything to do with the diet/fast directly. Its not good in general.
Oh! I just did a search, its red dye #40. (Article example: http://www.snet.net/features/qa/articles/2001/03160101.shtml) Ask your doctor or nutritionist if you should be aware of it and follow whatever advise they give YOU.
Take care,
Renay