So, I'm taking a request and writing about having friends with eating disorders: the pros and cons, and so on.
For me, there was a time in my life when having friends with EDs was very important to me. It was important to be with people who understood my anxiety around food and could have supportive meals with me, could send and receive support texts, and could just make me feel less alone. When you're friends with people from treatment, you're generally at a similar place, teetering around, walking a narrow balance beam, not too sure if you're going to fall into recovery or relapse. When things are that uncertain, you have so many differences from people who are not eating disordered that you really only may feel close to the friends with EDs, even if you're not always talking about eating disordered things with them.
Then, you may start to develop some distance from your eating disorder and realize that you don't actually have that much in common with most of the eating disordered friends you made from treatment or the internet. So you slowly move away from them. Around that time, you might also start to realize that you are able to connect with people without eating disorders. You might be cautious about this, because you're not sure how much of you they understand, or how much you want them to understand, but you're at a different place. Hopefully, a lot of your friends have followed you to this same mental place and you can still connect with them.
As more time goes by though, you might be lucky enough to be doing better in your recovery than other people. You can probably clearly remember a time when you were that friend who wasn't doing so well, but now you're making progress. Chances are, some of your original ED friends are doing well, and others have relapsed and might be back in treatment, or need to be.
For me, I reached a stage beyond this, where an eating disorder is no longer part of my life, but I do still have friendships that I formed as a result of the eating disorder. I have a few specific friends - M, J, and B - who I am thinking of in relation to this. M is someone who I've known from the time that I've been in treatment, and she's been struggling with her eating disorder for as long as I've known her. We live far away, so we don't see each other so often. She is able to maintain great conversations about things other than her eating disorder, and I think that this is a big part of why we have been able to maintain a great friendship despite her struggling while I no longer struggle. J is someone who I met through an ED friend who I met on facebook, but by this time, none of that matters. We're no longer friends with that mutual friend, but we are very close friends, and right now, we are both doing well with things. There have been times when J was struggling while I wasn't, and she basically keeps to herself when she isn't doing so well.While this isn't necessarily a good quality for her own mental well-being, I think that it allowed us to still maintain a good friendship thereafter. B is someone who I met when I was doing well, and she was struggling. She's told me that she looks up to me, and I think that that "mentorship" type of relationship is what has kept our friendship strong. In the beginning of our friendship, we exchanged lots of long, honest and open emails, and now I trust her so much. I have never been afraid to tell her when I am dealing with something, and she's always supportive. Right now, she is doing well too, and I'm so glad. I have a couple of other friends in various stages of recovery from eating disorders, but these are the people who I am closest with.
I've also had to say goodbye to people who were struggling, because they "triggered" me, or frustrated me, or I just felt like I couldn't relate to them anymore. I've also been that friend that people had to say goodbye to. So, having to distance yourself from friends with EDs is pretty common, but there are some people who you might find you're able to keep around. I don't think there's a formula of when you "have to" say goodbye to someone, but for the most part, if the person is taking up a significant part of your therapy session, that's a good time to insert some serious distance.