In his book Wij zijn ons brein (We are our brain), Dutch professor and neuroscientist Dick Swaab states that evidence suggests anorexia nervosa is a neurological disorder. (page 173) It appears to be a disorder in the hypothalamus. There is absolutely no reason to believe this disorder is caused by media attention.
Additionally, a case of anorexia nervosa has been found found in a 19-year old woman who has been blind since birth.
Below is a summary of Swaab’s conclusion:
The current trend seems to be that anorexia is an infectious disease,
similar to the way people thought homosexuality was an infectious disease some
time ago. In both cases, there is absolutely no evidence supporting
this. Being skinny might get one a job as a model, but skinny models
do not cause eating disorders. [He mentions the blind woman as not
supporting the idea that visual stimulus causes eating disorders.] In
fact, there is no evicence that the number of people suffering from
anorexia is increasing, although many dare to admit suffering from it now. All
symptoms indicate that anorexia is a disease of the hypothalamus. [He
then mentions functions of the body controlled by the hypothalamus
that are affected by anorexia as well, such as lower levels of sex
hormones, and how this could be an evolutionary advantage.] Several symptoms can still
occur after weight has been gained again. A tumour or cyst in the
hypothalamus can cause anorexia, and this was found to be the cause of
anorexia in several women. Of course this does not mean all anorexia
patients have a tumour in their hypothalamus, but it can be the cause.
It is not clear which disorder is involved here. It is clear that, apart
from sexual differentiation of the brain, genetic factors exist that increase the chance of getting anorexia. A few
directly involved genes are know. A very stressful event could seem a
direct cause of the disease, but factors who made the person
vulnerable to the disease probably had effect during the development
of the brain in the womb.The original process on which all that has
an influence, remains unknown. [Swaab mentions his favourite theory is
that it is an autoimmune disease.]