The need for control is thought to be one of the major causes of anorexia. These feelings stem from abuse, perfectionist expectations, or rigid rules where autonomy and independence are denied. In this sense anorexia can be seen as a family systems problem, and therapy in these cases needs to focus on creating a home environment that is more flexible and allows members to freely express themselves.
A common description of the anorexic is a Caucasian, teenage girl from a middle-upper class family who experiences difficult demands of perfection in all phases of life including school and extracurricular activities. Anorexia affects both sexes as well as all classes and races, but the aspects of perfectionism and lack of control are common among all cases.
She is backed into a corner where she feels that all aspects of her existence are outside of her active control. She has little say over the course of her life. These feelings are not necessarily experienced consciously but instead repressed. She tries to please everyone and usually sets expectations for herself that are difficult or impossible to attain and she struggles to meet the expectations of everyone else. Nothing is ever good enough, and even accomplishments are usually minimized or denied.
You can start to understand the psychological relief that comes from being able to take total control over weight management. You decide exactly which types of food enter your body, exactly how many calories you consume, exactly how much time you spend exercising, and you develop precise goals for weight loss. All aspects of food consumption become highly regimented. There is little outside intrusion at first since working out and dieting are generally accepted and even encouraged behaviors in our culture. You get to fly under the radar and feel a sense of total control over an essential aspect of your life that balances out feelings of helplessness.
This is why to beat anorexia one usually needs to have a safe space to learn about anxiety, the effects of abuse, and how internal and external standards of perfection contribute to the disease. You learn to separate yourself from the selfish needs of others in your family system and start to feel a real sense of control over important aspects of your development like your school work, career inclinations, interests and hobbies, and social life. Once you can achieve this, control over food consumption automatically becomes less important because it no longer provides the function of helping you to ignore the painful realities of your family situation.