To some extent I would agree with that. This is one of the things I am tending to learn about after the fact at this point, as the girls I did gymnastics with get older. On the other hand, while I hadn't really seen some things coming, in retrospect the pieces would fit to some extent. But it's hard to tell. I've heard a lot of girls say some variation of "I can't quit gymnastics because I don't want to get fat," but not all of them developed eating disorders. Some were joking, but for people who are really struggling with that idea, they don't necessarily pick up on it as a joke and it becomes another tidbit to fuel the obsession.
I don't think it's necessarily the coach or parent's fault either. While coaches and parents can definitely accelerate concerns in a vulnerable time and should be careful, in my experience there's no blueprint for what you have to do to prevent an eating disorder, like if you just do the right things, your kids won't be affected. You could do all the right things and they can find the triggers elsewhere...from a friend at school who is restricting food, from pro-ana websites, even from the compliments they get about being thin. I think part of the problem with eating disorders is first, how often people throw around the label "anorexia" when it's not really the case, until it almost becomes some kind of joke, and second, that there's kind of a viewpoint that it takes a lot for someone to get to the point of an eating disorder. And I don't think that's true. It's not always one thing that sets it off...it can be a lot of little things that someone who isn't trapped in thoughts about body images doesn't pick up on.