Therapists pretty much agree that there are three main causes of eating disorders, and most of us who get them have a combination of the three. One is your genetics. Second is your physiology, like the biology of your actual brain—your personality. Some people are incredibly resilient and slough off difficult messages; other people are not. In my book I call them Velcro; things stick to them. I’m Velcro. The third thing is environment. Environment is broken into two parts: the environment of your home, what your mom and dad said to you, the behaviors they modeled. The other part of environment is culture. So about one-sixth of eating disorders can be blamed on cultural environment, like the pictures we’re shown. That’s what I mean when I say skinny models don’t cause eating disorders. I just think that’s completely oversimplified and kind of ridiculous. If we magically were able to suddenly change the images we see in order to be diverse in all ways, gradually that part of the pressure would relieve itself. But it wouldn’t relieve that need of a girl to control her food intake because she can’t control her life.A lot of this must be oversimplifying. Genetics and physiology are intertwined, so any attempt to separate them as causes must be a little arbitrary. She also exaggerates her own position when she jumps from "about one-sixth of eating disorders can be blamed on cultural environment" to "I say skinny models don’t cause eating disorders."
Still, I think there is something basically right here. It jibes also with the stories reported in conjunction with the trend of exporting the American style of mental illness. (See also here.) People in Hong Kong used to develop a form of anorexia different than the American model. They refused to eat, but not because they thought they were fat. However as more American culture got picked up in the Chinese speaking world, the way people talked about the illness changed. It became something about women wanting to look thin when it wasn't before.
The fact that a style of mental illness can be based in a culture and then exported is fascinating in itself. But what is also interesting is that we can talk about anorexia separately from its current cultural connotations. Even minus the skinny models, people can develop pathological desire not to eat.