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

Abstract

WHAT'S KNOWN ON THIS SUBJECT:The prevalence of overweight and obesity in US adolescents has increased over the last century. However, recent evidence indicates a potential change in this trend. Parallel trends in adolescent behaviors that drive this epidemic have not been well studied. WHAT THIS STUDY ADDS:Analyses of recent data indicate the prevalence of overweight and obesity may be stabilizing. Over the same period, adolescent physical activity, breakfast eating, and fruit and vegetable consumption increased and television viewing and consumption of sweets and sweetened beverages decreased. abstract OBJECTIVE: The high prevalence of adolescent obesity in the United States has been attributed to population changes in physical activity (PA), sedentary behaviors, and dietary behaviors. This study examines 8-year trends in these behaviors in US adolescents ages 11 to 16. METHODS:Nationally representative samples of US students in grades 6 to 10 were recruited during the 2001-2002 (N = 14 607), 2005-2006 (N = 9150), and 2009-2010 (N = 10 848) school years by using multistage stratified designs, with census regions and grades as strata, and school districts as the primary sampling units. African-American and Hispanic students were oversampled to obtain better estimates for those groups. Using the Health Behavior in School-aged Children quadrennial surveys, identical questions assessed BMI, PA, and sedentary and dietary behaviors at each school year. Logistic and linear regression analyses were conducted taking into account the sampling design and controlling for age, gender, race/ethnicity, and family affluence. RESULTS:Across the quadrennial surveys, significant increases were identified in number of days with at least 60 minutes of PA, daily consumption of fruits and vegetables, eating breakfast on weekdays and weekends, and BMI. Television viewing and consumption of sweets and sweetened beverages decreased across this same period. These same patterns were seen in all racial/ethnic groups.CONCLUSIONS: These patterns suggest that public health efforts to improve the obesity-related behaviors of US adolescents may be having some success. However, alternative explanations for the increase in BMI over the same period need to be considered. Dr Iannotti conceptualized and designed the study, coordinated and supervised data collection, contributed to the analysis, and drafted the initial manuscript; Dr Wang contributed to the conceptualization of the manuscript, carried out the initial analyses, and reviewed and revised the manuscript; and all authors approved the final manuscript as submitted.www.pediatrics.org/cgi

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