Many people say it is heredity that transfer the particular characteristic from the parents to their kids. In terms of weight and eating habits, heredity also plays a role in developing eating habits of kids. At least, that is what I heard from my parents. "No wonder that person is so fat or eat so much, their parents did too"
The question now come back to which element foster eating disorder? It is it within your gene or family traits to developed eating disorder? Sisters that are biological twins have higher % of suffering eating disorders at the same time compared to non-biological sisters. There are some heredity links that are associated with eating disorders. In another theory, genetic heredity leads to genetic transfer of gene that produces higher level of stress that are associated to repetitive actions that led to eating disorder.
The argument that eating disorders is not only heredity but also a learned habit is probably the best explanatory for the occurrence of eating disorders. Communities especially parents play a huge role in our life. Appearance and other's perception matters. Society seeks for smaller size body appearance. Thin are thought as success while being fat equate to failure. Media exposure through ads and movie stars that are appears to be thin and pretty confirms the success of thin person. Comments from family members about the body size are also being taken seriously.
While patients cannot stop compulsive eating, they can use other methods to off-set the calories and thus, create and prolong the habit of eating disorders. Some patients just want to be slim. Some even does that to gain attention from their family and peers.
While being slim might equate success, the act of binge and purge are damaging to your body and a waste of food. There is potential for nutrient losses and thus, lead to nutrient deficiency. In young lady, it might also lead to the stop of period cycle and thus, speeding the loss of calcium from your bone. Loss of calcium makes you prone to bone fracture especially during intense exercise.
The genetic of eating disorder. http://www.ncbi.nlm.nih.gov/pubmed/21243475
Helder SG1, Collier DA.