I've never attempted fasting, and now that I've got lupus, I don't think I'd try it - for all the reasons Saysusie listed.
I have however, adjusted my diet since being diagnosed. I eat a little fish and shell fish, but no other meats. I try to eat only natural foods, whole grains, organic, with as little processing as possible. I've heard it called a "mediteranian" diet, high in olive oil, fresh vegetables and fruits, some cheese (I love goat cheeses!), nuts and beans for protein, and such. I believe it made a difference for me in lowering pain and increasing energy. Plus I lost some weight!
~"I find hope in the darkest of days, and focus in the brightest. I do not judge the universe." (Dalai Lama)