Yes, I remember at the time I was also taking abnormal psychology, and I found it interesting that the professor said, "most eating disorders start out as restrictive diets." That makes so much sense, because you get on a high from restricting and resisting, and then it spirals when you start hearing excessive praise...especially if you were insecure and/or unattractive to start with. I'd imagine Chelsea has always been considered attractive by most people, but she's definitely insecure. And the whole theory about restrictive diets makes sense, because I've experienced it on a smaller scale. It is so much easier to resist foods when you're seeing results, but most of us just don't have extreme personalities, so we eventually cheat on the diet, or find restricting past a certain point unsustainable.
another interesting thing I have carried with me from psychology is, "don't compare yourself to people in the media. They're in the top 1% of attractiveness, and they're getting paid to look that way...AND they're so edited that even they don't actually look like that!" Chelsea actually is part of the public eye, and I hope she doesn't feel she has to compete with movie stars and reality personalities who are truly in that 1% of looks. She's a beautiful girl compared to society at large, but nobody can compete with movie stars and supermodels. They all, with very few exceptions, have the naturally reedy thin frame that Chelsea does not, and it's okay that she doesn't.
I was worried about her at one point, but now she doesn't share enough about her eating habits for us to know, one way or the other. The best we can hope for is that IF there's a problem, someone close to her will spot it before it's too late.