Now medical students at 155 colleges in the United States and abroad can do just that, thanks to an interactive program that the University of North Carolina's Public Health School recently made available on its online nutrition and medicine series.

Advisers from 15 medical schools as well as a University of North Carolina at Chapel Hill team of physicians, dietitians, software experts and graphics specialists worked on the training material.

Dr. Steven Zeisel, the UNC pediatrician who oversaw creation of the program, said doctors-to-be, especially pediatricians, need to pay attention to nutrition and weight issues in children.

Roughly a third of U.S. kids ages 2 to 19 are either overweight or on the verge of becoming so, according to the Centers for Disease Control and Prevention. Medical experts say they've seen a rise in the number of young people with diabetes, which often is tied to obesity.

Zeisel recently answered questions about the program.

Q: What happens once a pediatrician determines a child is overweight?

A: They have to decide when is the threshold for when they take valuable time with the patient to deal with it. We're trying to teach them that they do it not when the child is in the top 2 percent of body weight for children but when the child crosses the growth line and starts to be gaining weight above the trend that they've been on. Two things they have to worry about. One, what are the food habits that the mother, the family and child are engaged in? And two, what are the exercise habits and how can you get more exercise and a better selection of food as early as possible?

Q: How do students use your training segment?

A: Our computer-assisted teaching program tries to, in a friendly and interesting way, bring the issues forward, present the science that the physician never got in medical school and give them some tools -- questionnaires, forms and other strategies.

Q: Have you seen a change in attitudes about children's weight?

A: There was a long period of time when having a fat child made parents feel that they had a healthy child. Grandmothers used to pinch those nice chubby cheeks and be really happy to see a child that way. It's only in the last, I'd say, five or six years you see more and more (parents) say, "I'm worried about my child being overweight because it is going to stick with them for the rest of their lives."

Q: What can parents do?

A: Parents should take an honest look and ask if their child is overweight. If you decide your child is overweight, then as soon as possible talk to your health practitioner about what you can do in terms of stopping that weight gain.

Exercise for children are games. They don't have to go to the gym. I think families exercising together is great.

Your children learn from you. If you sit on the couch and watch TV, you're teaching your child a lesson that is going to cost them for the rest of their lives.