Narrator: This is Science Today. The number of adolescents in this country may be on the rise, but are they healthy? Psychologist Elizabeth Ozer of the University of California, San Francisco says that all depends on how you measure health.

Ozer: Well, adolescents, quote, are healthy if you look at what’s traditionally been looked at measures of health: do they have heart attacks, do they have cancer, what are they dying of, are they dying of illnesses? No they are not dying of traditional illnesses.

Narrator: But Ozer says many adolescents are taking risks by not exercising, getting poor nutrition or using drugs. These behaviors, Ozer says begin during adolescence and are associated with poor adult health and death..

Ozer: So, what you’re seeing here is that there are a lot of things we have to be concerned about what’s happening in the adolescent years but they haven’t been looked at quote, under traditional health markers.

Narrator: Ozer says more prevention programs are key to keeping adolescents thriving. For Science Today, I’m Larissa Branin.