According to a research conducted by Benn and Walters (2001), dancers studied were found to only consume 700 to 900 calories per day. Many of the subjects were consuming less than 700. Surveys conducted in the United States, China, Russia, and Western Europe by Hamilton (1998) found that female dancers’ weights were 10 to 15 percent below the ideal weight for their height.
That's just not good for anyone, and the paper details that a bit more. It also mentions how that is largely (though not totally) a US problem. And perhaps that's largely the result of US culture in general, which is so emphatic on how thin women "should" be.
I wonder if all that is a bit of background on why the character Boo in Bunheads is there. I hope that, showing her (Kaitlyn Jenkins, the actress, that is) having some success, it helps people in power in ballet companies see that it might not be such a disaster to have normal, healthy women as their stars, rather than waifs. Kudos to the makers of that show.
In fact, I didn't think about it until I wrote the rest of that, but we also saw, in the first episode, how a dance audition can end before it begins, although they attributed it to age rather than body profile.