Eating disorder predisposition toward eating disorders as a result of Mendelian inheritance. Twin studies have found a slight instances of genetic variance when considering the different criterion of both anorexia nervosa and bulimia nervosa as endophenotypes contributing to the disorders as a whole. A genetic link has been found on chromosome 1 in multiple family members of an individual with anorexia nervosa. An individual who is a first degree relative of someone who has had or currently has an eating disorder is seven to twelve times more likely to have an eating disorder themselves. Twin studies also show that at least a
Eating disorder is also seen within the homosexual community. Homosexual men are at greater risk of eating disorder symptoms than heterosexual men. Within the gay culture, muscularity gives the advantages of both social and sexual desirability and also power. These pressures and ideas that another homosexual male may desire a mate who is thinner or muscular can possibly lead to eating disorders. The higher eating disorder symptom score reported, the more concern about how others perceive them and the more frequent and excessive exercise sessions occur. High levels of body dissatisfaction are also linked to external motivation to working out and old