I have a friend and she is showing symptoms of eating disorders, and she has even confided in people about it to a certain degree. but now she is denying ever saying these things and she went to the doctor and he couldn't find any of the medical symptoms, so now i'm trying to figure out why.
It takes a long time for an eating disorder to take a toll on the body and start creating medical symptoms. Sometimes bulimics have no symptoms but bad breath and teeth problems (which a doctor wouldn't look for) until they have a heart attack. Anorexics obviously show signs when they lose enough weight to look horrible. everyone is different though, so your friend may just be lucky enough to not have any symptoms for a while. you should still try to help her though. tell her parents, or at least your school counselor for advice.