Trends in overweight prevalence among 11-, 13- and 15-year-olds in 25 countries in Europe, Canada and USA from 2002 to 2010

Background: The purpose of this study was to assess recent changes in the prevalence of overweight (including obesity) among 11-, 13- and 15-year-olds in 33 countries from 2002 to 2010. Methods: Data from 25 countries from three consecutive survey cycles (2002, 2006 and 2010) that had at least 80% response rate for self-reported height, weight and age were analysed using logistic regression analysis. Results: Overweight prevalence increased among boys in 13 countries and among girls in 12 countries; in 10 countries, predominantly in Eastern Europe, an increase was observed for both boys and girls. Stabilization in overweight rates was noted in the remaining countries; none of the countries exhibited a decrease over the 8-year period examined. In the majority of countries (20/25) there were no age differences in trends in overweight prevalence. Conclusion: In over half of the countries examined overweight prevalence did not change during 2002-2010. However, increasing overweight prevalence was noted in many Eastern European countries over this time period. Overweight prevalence remained high in several countries in Europe and North America. These patterns call for continued research in youth overweight and highlight the need to understand cross-national differences by examining macro-level indicators. Such research should feed into developing sound translations and practices to prevent and reduce overweight in youth.