Researchers found teens trying to drop the pounds don't seem to fully understand the link between exercise and calories.
The study of nearly 44,000 adolescents found that, among the obese, girls who exercised still drank soda and boys didn't exercise at all.
Also, 75 percent of the obese teens trying to lose weight were more likely to smoke, possibly as a weight loss aid.
Scientists say, if teens are trying to lose weight, doctors need to ask follow up questions to find out how they are going about it and give suggestions on how to modify their behaviors.
