That would depend on what your eating disorder is, if it is that you are prone to overeating, it is going to be difficult to lose weight, on the other hand, if you have a eating disorder like anorexia or bulimia, you will lose weight.
You can lose or gain weight. An eating disorder could be you don't eat at all or you eat too much, such as seeking food for comfort.
Anorexia Nervosa
Yes.
Yes, however this is almost never recommended. Vomiting to lose weight is a serious eating disorder called Bulimia.
you lose it in a healthy way. you don't let it take over your life, and you don't get obsessed. you lose weight just to be healthy, not thin.
Bulimia
Yes and No. If you do have binge eating disorder and want to lose weight, you should try to eat a stable diet without binging for a couple of weeks before exercising. If you cant do this talk to a doctor.
obsessive compulsive over eating Binge-eating disorder
a eating disorder is really unhealthy for the body and once youve gain so much weight its gonna get hard to lose a few pounds
Almost certainly yes. A disorder means a lack of order. Eating regularly and healthily is order, starving by choice is disorder. It's as simple as that.
Bulimia nervosa.
This doesn't sound like an eating disorder (unless the friend is bingeing/purging) . It sounds like depression. When someone is depressed, they often gain weight and don't have the energy to lose the weight that they want to.