Some sources say that the United States is the country with the largest number of anorexics and one other source says that China purportedly has the highest number. Most sources report that anorexia is found predominately in Western cultures and is the result of a number of factors. In Western cultures, many of theories point to a genetic connection within families. Then, there has also been a correlation between the incidence of this particular eating disorder and other psychological disorders.
Finally, one of the biggest influencers is the effect of media images on society as a whole and the individual. While not the core issues, many believe that unrealistic depictions of beauty and youth can create unrealistic expectations of body images, which can exacerbate this condition.
In China, one of the explanations relates to the society being one in which control and discipline is important. Incidentally, the condition is marked by a need for the individual to feel a sense of control, and so in this context, anorexia manifests itself culturally in this way. While the other two factors (genetics and mental health) play a role, again, culture plays a large role in how this condition is treated.