Question: What causes an eating disorder? I am a little confused about what causes an eating disorder. Is an eating disorder caused by trying to be skinny and then having that get out of control and causing changes and malfunctions in the brain? Or is an eating disorder caused by trying to control your emotions and control the world by controlling what you eat? I am trying to understand a family members anorexia and I find that it is hard to get a clear answer what it’s really caused by. Can you help to shed some light on this for me?

Dr. Lani Chin Says...:

Thanks for your post. I'll try my best to answer your question.

Here is what a psychologist or mental health professional uses to diagnose anorexia:

A. Refusal to maintain body weight at or above a minimally normal weight for age and height (e.g., weight loss leading to maintenance of body weight less than 85% of that expected; or failure to make expected weight gain during period of growth, leading to body weight less than 85% of that expected).

B. Intense fear of gaining weight or becoming fat, even though underweight.

C. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body shape on self-evaluation, or denial of the seriousness of the current low body weight.

D. In postmenarcheal females, amenorrhea, i.e., the absence of at least three consecutive menstrual cycles.

Type: Restricting Type vs. Binge-Eating/Purging Type.

This is taken directly from DSM-IV. American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Washington, DC.

So to answer your question, there are a few components to an eating disorder. There are physical and emtional factors that impact disordered eating. It's difficult to say if it's the brain that is malfunctioning or someone's need to control their emotions. While these are both certainly relevant, they cannot fully explain why someone may or may not have an eating disorder. I hope this helps. Good luck to you and your family member.

Question: Is it possible to have a bmi of 13 and not be an anorexic? I just did a calculation of what my 15 year old daughter weighs and how tall she is and she is a 13.2 bmi. I am worried about her and but I am not sure how to know if she has anorexia or not.

Dr. Lani Chin Says...:

There are other factors to consider when looking at a diagnosis of anorexia.  Anorexia nervosa is defined by the American Psychiatric Association as a
medical condition whereby individuals do not maintain a normal body
weight, fear gaining weight, experience body image disturbances, and, in
females, miss three consecutive menstrual cycles. Anorexia is an often
fatal condition, and many individuals who have anorexia often have other
psychological and physiological problems.  It is difficult to diagnose only knowing your daughter's BMI.  For a 15 year old female, however, a BMI of 13 seems incredibly low.  I would recommend you take her to see a pediatrician to confirm the diagnosis.  Good luck to both of you.