Ther're just putting into words what Hollywood and the fashion industry have been telling women for years.
You hit that nail on the head.
Also from a pro-Ana website:
ANA CREED
I believe in Control, the only force mighty enough to bring order to the chaos that is my world.
I believe that I am the most vile, worthless and useless person ever to have existed on this planet, and that I am totally unworthy of anyone's time and attention.
I believe that other people who tell me differently must be idiots. If they could see how I really am, then they would hate me almost as much as I do.
I believe in oughts, musts and shoulds as unbreakable laws to determine my daily behaviour.
I believe in perfection and strive to attain it.
I believe in salvation through trying just a bit harder than I did yesterday.
I believe in calorie counters as the inspired word of god, and memorise them accordingly.
I believe in bathroom scales as an indicator of my daily successes and failures.
I believe in hell, because I sometimes think that I'm living in it.
I believe in a wholly black and white world, the losing of weight, recrimination for sins, the abnegation of the body and a life ever fasting.