My sister has an eating disorder? My sister won't eat unless we are all there and even then she only eats about three bites of whatever it is and then she says she doesn't feel well. Later I find out she is puking up everything she eats. In 5 days she lost six pounds and she is happy about it. I have tried to convince her that she is thin enough and she needs to stay healthy but she won't listen to me or my father let alone her own mother. Any advice?

Summarized question: How can i help someone with an eating disorder?