THE BEST TREATMENT for eating disorders, as with any illness, is prevention. Teenagers who feel good about themselves and who have a positive and healthy attitude toward their bodies are less likely to develop eating disorders. Some schools now have programs in which young people learn to value themselves. Eating disorder organizations, too, offer educational programs to increase awareness of society's obsession with being thin.

Looking at weight realistically

One way teens can help themselves is to look at their weight realistically and to understand that superslim models and actors are underweight. The female body is supposed to have some fat in preparation for childbearing. "If society were in concert with how females actually develop, we'd celebrate the rounding of the female shape around puberty," says Yale University professor of psychology Kelly D. Brownell. "But because women are told to...