Adolescents: Bending the Obesity Curve Interview with:
Ronald J. Iannotti, PhD
Prevention Research Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland

Trends in Physical Activity, Sedentary Behavior, Diet, and BMI Among US Adolescents, 2001–2009 What are the main findings of the study?

Dr. Iannotti: Although average BMI percentile increased from 2001 to 2005 it did not increase from 2005 to 2009. This is consistent with some recent studies that suggest the increase in overweight and obesity may be leveling off. We suggest that we may be ‘bending the curve’. During the same period, physical activity and consumption of fruits and vegetables increased while television watching and consumption of sweets and sweetened beverages decreased. We cannot say whether television watching was replaced with more time spent on computers but we did not find an increase in computer use from 2005 to 2009. Were any of the findings unexpected?

Dr. Iannotti: YES! . Over the past four or five decades adolescent overweight and obesity have steadily increased along with television watching and consumption of foods high in sugar, while physical activity and the relative consumption of fruits and vegetables has decreased. These results are very encouraging. This would be the first decade in a long time where overweight did not increase substantially and where healthful behaviors increased. What should clinicians and patients take away from your report?

Dr. Iannotti: There is still lots of room for improvement. Most adolescents are not getting 60 minutes of moderate to vigorous physical activity and day and the consumption of fruits and vegetables is not even close to the recommended 5 servings per day. Because of gender differences, clinicians might focus on increasing physical activity in girls and decreasing their consumption of sweets. For boys, the focus might be on diet and television, decreasing television watching and increasing fruits and vegetables.

For parents, they should continue to encourage their children to get more exercise and to eat fruits and vegetables. Some types would be to demonstrate the behaviors they want their children to adopt. For example, they could take a walk after dinner with the entire family. When their children do watch television, they could make sure that healthful snacks (for example, cut up fruits and vegetables) are easily available. We tend to be lazy and having good choices easily available makes it more likely that we will make those choices. What recommendations do you have for future research as a result of this study?

Dr. Iannotti: We need to continue to monitor these trends and identify whether the changes in health behaviors are causing this change in the rate of growth in the obesity epidemic.


Trends in Physical Activity, Sedentary Behavior, Diet, and BMI Among US Adolescents, 2001–2009

Ronald J. Iannotti and Jing Wang

Pediatrics peds.2013-1488; published ahead of print September 16, 2013, doi:10.1542/peds.2013-1488