Some agencies turn the other way, but I've seen my agency immediately address the girls with severe eating disorders. It shocks me that people say bookers encourage drug use/disordered eating, because I've never seen this.
Without giving too much away, they promote healthy eating with heavy workouts, so when one of their development girls has an eating disorder they address the problem immediately.
It's best in the long run, and models who have long, enduring careers make them the most money. Even if several of the agency's girls have been mentioned on this site as being "too large", there's no denying the fact that they bring in millions each year.
Long story short, yes they care. I'm sure some VIPs/insiders with other agencies could provide you with an entirely different answer though.