Risk Factors
Many factors contribute to the risk of developing an eating disorder.
Age
Dating disorders occur most often in adolescents and young adults. However, new research finds that they are increasingly prevalent among young children. Eating disorders are more difficult to identify in young children because they are rarely suspected.
Text Continues Below

Age of Onset for Bulimia. A 2004 study of high school students in the United States found that about 25% of girls and 10% of boys followed abnormal eating and weight control practices. Another study found that 2% of adolescent girls and 0.3% of adolescent boys fulfilled the criteria for bulimia. The average age of onset was 17.2 years. According to estimates, as many as 10% of college-aged women have bulimia. Some experts claim that even these percentages grossly underestimate the problem because many people with bulimia are able to conceal their purging and do not become noticeably underweight. For example, a European study detected bulimic behavior in 14.4% of adolescents 14 to 16 years old, with full-blown bulimia observed in 1.8% of girls and 0.3% of boys.
Age of Onset for Anorexia Nervosa. After asthma and obesity, anorexia nervosa is the third most common chronic illness in adolescent women. It is estimated to occur in 0.5% to 3% of all teenagers. Anorexia usually first occurs in adolescence with peaks at 13 to 14 years of age and at 17 to 18 years of age. Over the past 40 years, however, the incidence has been steady in teenagers, but it has increased threefold in young adult women.
Gender