I agree. If you get confrontational it will make you look like the out of control, overly defensive one. Be clear, be rational, and calmly explain to the doctor what you have already stated here. If you have a few days (week would be better) before the doctor's appointment I would start keeping a food diary. I don't think I would necessarily show it to the doctor to start with BUT it would help you be able to better remember what you have eaten over the course of at least the past few days and you would be able to bring it up... such as, how am I anorexic if I had xyz for breakfast, abc for lunch, and efg for dinner? See, I am just eating reasonable and healthy. They are obviously the ones with the eating disorder. At this point though I just think you are playing a waiting game... waiting to turn 18 and get the hell out of there.  If your family escalates things from here then yes, I would check out the emancipation thing.