Among the boys in the study, those most at risk worried that their bodies were puny — too small, too skinny or insufficiently muscular, prompting them to consume unbalanced diets, exercise obsessively and take supplements or steroids that are a hazard to their health. When overly fixated on building their bodies, they can become socially withdrawn and depressed and develop a disorder called muscle dysmorphia that can lead to heart failure, resulting from insufficient calories and overexertion.
A missed diagnosis is likely when a young person’s relatives or doctors have preconceived notions about how someone with an eating disorder looks or behaves. For example, Dr. Nagata said, a teenage girl or young woman who is anorexic can fall under the medical radar because her weight is normal or even overweight.
Although diagnosis of an eating disorder like anorexia or bulimia was twice as common among the young adults whose weight was normal or underweight, the fact that these disorders also exist in heavier young adults is often overlooked, Dr. Nagata said.
“Almost half of those with anorexia nervosa are at or above normal weight,” he said. “Young people with atypical anorexia have the same body image distortions and severe psychological distress as those with regular anorexia. They’re at high medical risk and just as likely to be hospitalized for complications caused by their distorted eating behaviors.”
Dr. Nagata’s colleague and co-author of the study, Dr. Kirsten Bibbins-Domingo, an internist at the university, said in an interview, “Physicians who care for young adults should think about patterns of eating that are harmful, and not just among very thin women. Young adults with abnormal eating habits too often fall between the cracks because physicians think of them as healthy. However, abnormal eating patterns are not uncommon in adolescence and young adulthood, and that’s when patterns of behavior related to later health and disease are established and solidified.”
The problem of disordered eating behaviors among teens and young adults is often encouraged or compounded by participation in certain competitive sports and other activities that overemphasize a particular body weight and physique. Among these are gymnastics, wrestling, dance, figure skating, weight lifting and bodybuilding.
Social media, with its heavy focus on appearance, has fostered the problem as well, Dr. Nagata said. Even toys, like Barbie dolls and action figures, have made a contribution. “A study of male action figures found that they have become bigger, more muscular and more extreme in their appearance over a 30-year period,” he said.