Our study is the first one of its kind because we followed the same people over time, looking at changes in their behavior.

A lot of these trends are to be expected. This is the age when young people experiment with different lifestyles and behaviors, and when they move out of the house they have even more freedom to do that. We expect that when they settle into more permanent jobs and unions, these trends will abate.

Diet got worse, people got less exercise, had less access to health care, there was a lower health insurance rate. Young adults drink more, smoke more cigarettes, use drugs.

Maybe this is a transitional period with no impact. Maybe these young people get married, cut back drinking, quit smoking and their diet improves. I can't wait to find out.

That means that there are no simple, across-the-board solutions for addressing health disparities. Instead, solutions must be sensitive to the different patterns of health risk that emerge across population groups as adolescents enter young adulthood.

This is not a story where minorities are always worse off. It really depends on what behavior you are looking at.