I'm with Paul on that I really don't know any men who like unnaturally thin women. My wife was a 10-12 and that was perfect because she was curvy and natural. I remember her when she was 17 or so being a 6-8 ish? and that was fine too because that was her natural size.
The issue with anorexia, is that it's a symptom of a feeling of lack of self worth, and you have to look far more broadly than a magazine page to initiate that, you have to look at friends, family, school, life experience etc of the individual.
I think size zero models should not be an issue, they arent relevant and we give this idea of superstar emulation too much credence. I am 99.9% sure that, like Pippa, my daughters will be raised to be their own people and won't encounter this disorder, that may sound arrogant and I may be wrong, but anorexia is NOT caused through thin models, it's caused by lack of self esteem and that is given to you far closer to home.