Eating Disorders May Run in Families

A study of twins shows that "56% liability for developing anorexia nervosa is due to genetic factors".

Another study of binge eaters "found that 20% of those with an immediate relative with binge-eating disorder had ever had the same problem, compared with 9% of those whose relative didn't have binge-eating disorder. The study doesn't show why binge-eating tended to run in families. Genes and environment could both be factors, but it's not clear how much either contributed."