Increasingly, research shows that chronic aliments, such as obesity, are affecting more and more of our children each year. Throughout our nation, people are demanding action to combat rising obesity rates in children and in controlling healthcare costs. But we need to look to prevention first. And where do we start? With living healthy lifestyles, eating right, and getting regular exercise. While changing these behaviors sound simple, doing so is complex, as illustrated in the excellent set of articles in this supplement to the American Journal of Preventive Medicine. 1 Chaloupka F.J. Johnston L.D. Bridging the gap: research informing practice and policy for healthy youth behavior. Am J Prev Med. 2007; 33: S147-S161 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 2 Delva J. Johnston L.D. O’Malley P.M. The epidemiology of overweight and related lifestyle behaviors: racial/ethnic and socioeconomic status differences among American youth. Am J Prev Med. 2007; 33: S178-S186 Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar , 3 O’Malley P.M. Johnston L.D. Delva J. Bachman Schulenberg Variation in obesity among American secondary school students by school and school characteristics. Am J Prev Med. 2007; 33: S187-S194 Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar , 4 Johnston L.D. Delva J. O’Malley P.M. Sports participation and physical education in American secondary schools: current levels and racial/ethnic and socioeconomic disparities. Am J Prev Med. 2007; 33: S195-S208 Abstract Full Text Full Text PDF PubMed Scopus (147) Google Scholar , 5 Johnston L.D. Delva J. O’Malley P.M. Soft drink availability, contracts, and revenues in American secondary schools. Am J Prev Med. 2007; 33: S209-S225 Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar , 6 Delva J. O’Malley P.M. Johnston L.D. Availability of more-healthy and less-healthy food choices in American schools: a national study of grade, racial/ethnic, and socioeconomic differences. Am J Prev Med. 2007; 33: S226-S239 Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar , 7 Powell L.M. Chaloupka F.J. Bao Y. The availability of fast-food and full-service restaurants in the United States: associations with neighborhood characteristics. Am J Prev Med. 2007; 33: S240-S245 Abstract Full Text Full Text PDF PubMed Scopus (242) Google Scholar , 8 Slater S.J. Powell L.M. Chaloupka F.J. Missed opportunities: local health departments as providers of obesity prevention programs for adolescents. Am J Prev Med. 2007; 33: S246-S250 Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar , 9 Powell L.M. Szczypka G. Chaloupka F.J. Adolescent exposure to food advertising on television. Am J Prev Med. 2007; 33: S251-S256 Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar , 10 Emery S.L. Szczypka G. Powell L.M. Chaloupka F.J. Public health obesity-related TV advertising: lessons learned from tobacco. Am J Prev Med. 2007; 33: S257-S263 Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar , 11 Powell L.M. Chaloupka F.J. Slater S.J. Johnston L.D. O’Malley P.M. The availability of local-area commercial physical activity–related facilities and physical activity among adolescents. Am J Prev Med. 2007; 33: S292-S300 Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar , 12 Powell L.M. Auld M.C. Chaloupka F.J. O’Malley P.M. Johnston L.D. Associations between access to food stores and adolescent body mass index. Am J Prev Med. 2007; 33: S301-S307 Abstract Full Text Full Text PDF PubMed Scopus (355) Google Scholar , 13 Mâsse L.M. Frosh M. Chriqui J.F. et al. Development of a school nutrition-environment state policy classification system (SNESPCS). Am J Prev Med. 2007; 33: S277-S279 Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar , 14 Mâsse L.M. Chriqui J.F. Igoe J.F. et al. Development of a physical education-related state policy classification system (PERSPCS). Am J Prev Med. 2007; 33: S264-S276 Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar