In the film, The Black Swan, Nina obsesses about being a perfect ballerina. Her dancing in a troupe is inextricably tied to her sense of self. To endanger that activity is an intolerable nightmare. To stop dancing or to lose progress toward unapproachable stardom is equivalent to the death of her identity.
Anorexic and bulimic women in real life go into weeping tantrums, rages, manipulative arguments and pleading when their eating disorder symptoms prompt family or medical advisers to suggest even temporary life changes in support of their health and psychological well-being.