Why does this "Anna Rexia" Halloween Costume even exist?

Why on earth does this Halloween costume have to refer to anorexia? It just looks like a skeleton to me. X-Rays, Zombies, bones--all that is ghoulish enough to fit with Halloween.

The description for this costume is the worst part: "If Anna Rexia doesn't want to put it in her mouth there is nothing you can say to change her mind. You can stop trying to sell her on the point that there aren't any carbs and it's all protein because Anna Rexia just doesn't want anything to do with it. Make no bones about it this girl is as disciplined as they can get. Anna Rexia costume is anything but bare bones! Costume includes headband, choker neckband, removable "Anna Rexia" badge and ribbon tie belt. If you're starving for attention, this costume will be sure to put you on top of the world."

It seems that the prevalence of anorexia has turned it into a common cultural fact, so part of our collective consciousness that, as with ads, we're almost immune to how serious (and unnecessary) it is.

Gross. And not in that fun Halloween way.