It is said that the most dehumanizing thing that a person can ever do is to remove their name, which is why the girl in the story is no longer referred to as Margie, but 500, as in 500 calories.  When the only thing that you are is a number, your sense of worth is immediately eradicated, which is exactly what an eating disorder is.

I think that this also gives an objective view into the mind of someone with a disorder such as bulimia because they don’t necessarily see themselves as an individual. Eating disorders are very obsessive-compulsive type behavior, and that’s what I was really looking to get across.