Anorexia nervosa, an eating disorder involving restriction of food intake, fear of becoming fat, and a distorted body image, afflicts 1 percent to 4 percent of women at some point in life.

In severe cases, anorexia can be life-threatening. A recent study indicates that psychological issues are not the only contributing factors.

Scientists studied the DNA of approximately 55,000 healthy control subjects and 17,000 patients who participated in the Anorexia Nervosa Genetics Initiative or the eating disorders working group of the Psychiatric Genomics Consortium.

They identified several genes that linked anorexia to mental symptoms, as well as genes that control physical activity, burning fat, and resistance to Type 2 diabetes.

The findings indicate that genetics explains approximately half of what contributes to anorexia, while life events and psychological factors contribute the balance of risk.

Eating disorders can be socially contagious within peer groups. Low self-esteem, poor body image, and peer pressure can all contribute to the development of an eating disorder.