There is a study in Preventive Medicine by the CDC examining the associations between insufficient sleep, defined as less than 8 hours on average on school nights, and health-risk behaviors. Researchers used survey data from 12,154 U.S. high school students. They found that sleeping less than 8 hours on school nights was associated with a higher risk of the following: cigarette, marijuana, and alcohol use; current sexual activity; feeling sad or hopeless and seriously considered attempting suicide; physical fighting, not being physically active, computer use at least 3 hours per day, and drinking soda more than 1 time per day. There was no difference in the amount of television watched between those who slept more or less than 8 hours.
The study authors concluded that insufficient sleep was associated with many health-risk behaviors and that lack of adequate sleep may be a warning sign for parents that their teenagers could have other problems.
I don't believe that the study authors think that teenagers will engage in more healthy behaviors if they get more sleep on school nights. I do wonder if the associations are as strong if teens make up for the lost sleep on the weekends.