It's stunning. We looked at 20 areas, and 16 out of the 20 showed declines in health indicators.

What's surprising is to see the decline in health across such a large array of outcomes.

Our hypothesis is that young adults are more vulnerable to poor health practices than teenagers because they are leaving the more protective environments of home and school.

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.

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.

The disparities vary so much. It isn't one race or ethnic group that's always worse off.