One negative experience, slight hair loss that started approximately 6 to 8 weeks post fast. Maybe 10 to 15% of the hair on my head fell out in total, but it all grew back.
One other negative experience but that was due to my own stupidity and I've since learned better.
Basically if you're above 15% bodyfat, you only need two things to live. Water and electrolytes.
If anyone has any questions, more than happy to answer e-mails.