For decades, eating disorders were thought to afflict mostly, if not exclusively, women and girls. In fact, until 2013, the loss of menstruation had long been considered an official symptom of anorexia nervosa.Over the last decade, however, health experts have increasingly recognized that boys and men also suffer from eating disorders, and they have gained a better understanding of how differently the illness presents in that group. A small but growing body of scientists and physicians have dedicated themselves to identifying the problem, assessing its scope and developing treatments.Recently, two of these experts spoke to The New York Times about how the disease is affecting adolescent boys, what symptoms and behaviors parents should look for, and which treatments to consider. Dr. Jason N...