Juice Fasting Guidelines for Normal Weight Person?

[Zaphod]

I am on the skinny side but would like to try juice fasting to take a step back from my eating habits and help reset my palette, as well as to compare my energy on the fast to see if any foods could be making me tired. I became really interested in trying this after watching Fat, Sick, and Nearly Dead, which despite the dramatic title is a pretty fun / entertaining documentary.

I do not want to lose much weight. I don't really want to lose any, but I realize losing a couple pounds is probably inevitable during it. I am having trouble finding any kind of doctor's guidelines or instructions for a juice fast for those that aren't overweight.

How many calories should I get per day? What kind of fruits or vegetables should I use? How much should I eat when breaking the fast? These are the kinds of answers I am hoping to find, preferably outlined from a holistic doctor or doctor of integrated medicine. Anyone know of a resource? Thanks..