Dr. Sanjay Gupta is known for his work with CNN, where he is chief medical correspondent. But Gupta, 43, also is an assistant professor of neurosurgery and a trauma neurosurgeon at Emory University’s hospital in Atlanta.

Q: Why do Americans struggle so with obesity?

A: The health illiteracy rate in our country is higher than people realize. There is no single answer. It is beyond eat less, exercise more, that is not a bad message; it is just not complete. Not all calories are the same, for example, and this has meaning for weight loss. Not all exercise has equal benefit either. Intense exercise in the morning, for example, ... can actually be damaging.

Q: What are the biggest misconceptions about American medicine today?

A: We’ve done such a good job at some things — heart research and cancer for example, and childhood leukemia. ... I think people can think they can live careless lifestyles (in diet, exercise, risky sexual behavior) and count on medicine to reverse or take care of these things. It just doesn’t work that way. By 2020 it is estimated that over half the country will be pre-diabetic or diabetic. The health care system will not be able to handle the surge of patients.

Q: How do we get better with our own health care?

A: Many seem so willing to hand off the decision-making to others. ... Many don’t research hospital emergency rooms in their community in advance ... It really comes down to being engaged.

Q: What are some good online sources?

A: EverydayHealth.com, Mayoclinic.com, and www.cnn.com/HEALTH/ are good. One caution ... is that people often go searching for information that will validate their own opinion. Given the vast array of information out there, they’ll likely find that, and the information may contradict ... their doctor. It could be good information, but it may not be.