I also went on a fast, after studying everything i could find on the subject. But none of the books and web sites warned me... After 20 days i felt a little strange nothing serious just a little shaky feeling but when i raised my hand it did not appear to be shaking. But, since i had never felt this before i went to the hospital. At first they thought it was kidney failure but it turned out to be my electrolites. all the water i had drank flushed them. I'm going to fast again but i'm definatly going to supplement with high mineral green juice like alfalfa and maybe seaweed. Most importatly day 5 to 18 i NEVER felt so good!