NEWS

Adolescent obesity largely caused by lack of physical activity, study finds

By WENDY TANSON
UNC School of Public Health

CHAPEL HILL -- An analysis of federal health data by a University of North Carolina at Chapel Hill nutrition researcher suggests that lack of physical activity, not excessive caloric intake, is responsible for the growing rate of adolescent obesity.

A report on the study will be presented Monday (April 14) at Experimental Biology ’03 in San Diego, one of the nation’s largest nutrition science professional meetings.

Dr. Lisa Sutherland found that, from 1980 through 2000, obesity increased 10 percent, physical activity decreased 13 percent and caloric intake rose 1 percent among U.S. adolescents. Sutherland, a post-doctoral fellow at UNC’s Lineberger Comprehensive Cancer Center and co-director of a research division in the clinical nutrition research center, housed in the UNC schools of public health and medicine, used national data sources to compare trends in these areas.

"Much of the debate regarding obesity has been focused on diet, yet there is evidence to suggest that activity plays a significant role in obesity for kids 12 to 19 years of age," Sutherland said.

"The decrease in physical education in schools, changes in transportation methods and popularity of television, video games and the Internet all contribute to an increasingly sedentary lifestyle for kids. Given these trends, it is crucial that we find new and creative ways to increase physical activity in adolescents as a first line of defense to combating obesity."

One of the data sets used for the study, the U.S. Centers for Disease Control and Prevention Youth Risk Behavior Survey, provided proxies for physical activity rather than precise measures, Sutherland said. She called for additional research to better understand physical activity trends for adolescents.

"In order to continue policy and program planning, we need better measures and a commitment to long-term longitudinal data collection from this population," she said.

In addition, Sutherland said policy-makers should focus on physical activity when addressing the problem of youth overweight.

"Our analysis of the Centers for Disease Control and Prevention and U.S. Department of Agriculture data demonstrates that policy focused heavily on restricting certain foods is failed policy," she said. "We should not have a discussion about the causes of obesity without talking about physical activity. Unless we can get our children moving, we will be unable to make any significant progress in terms of weight management."

Funding for the study was provided by an unrestricted grant from the National Soft Drink Association, which had no control over the analysis of the data.

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Note: Sutherland can be reached at (919) 966-5635 or lsutherl@email.unc.edu.

UNC School of Public Health contact: Lisa Katz, (919) 966-7467 or lisa_katz@unc.edu
UNC News Services contact: Deb Saine, (919) 962-8415