What if an emaciated person with anorexia nervosa asks me on how she looks like, how should i respond?

Honest- tactful: I think it is fair to be honest in a tactful manner. People with anorexia nervosa have distorted body images & reality based feedback can be beneficial. Just do so gently. Take care.

Honestly.: Anorexia nervosa is a medical disorder where the person has a distorted self image of themselves, and of what they consider as overweight/fat/obese... Of all the psychiatric illnesses, it has the highest mortality! the best way to approach a friend with this disease is to not humor them. State your concern, and ask them to been seen by a md, do who deals with this.