title: Bridging the Gap: research informing practice and policy for healthy youth behavior.
abstract: BACKGROUND
  Bridging the Gap (BTG) is a collaborative research initiative supported by the Robert Wood Johnson Foundation. Ten years ago, BTG was created to assess the impact of policies, programs, and other environmental influences on adolescent alcohol, tobacco, and illicit drug use and related outcomes. This multidisciplinary, multisite initiative examines these factors at multiple levels of social organization, including schools, communities, and states. More recently, the significant increases in obesity among children, adolescents, and adults led BTG to expand its efforts to include research on the role of policies, programs, and other factors on adolescent obesity and the physical inactivity and dietary habits that contribute to this growing problem. Eleven papers resulting from BTG's obesity-related research are contained in this supplement, along with two papers describing the National Cancer Institute-supported efforts to track relevant state policies.
  
  
  METHODS
  Bridging the Gap involves a variety of data-collection efforts built largely around the Monitoring the Future (MTF) surveys of 8th-, 10th-, and 12th-grade students. These include: surveys of administrators in the MTF schools that gather extensive information on the school food environment, physical education in schools, and other relevant information; collection of contextual information from the communities in which the MTF schools are located; tracking of relevant state policies; and gathering of a wide variety of data from archival and commercial databases. These databases are analyzed individually and in various combinations.
  
  
  CONCLUSIONS
  Bridging the Gap's extensive research has shown the importance of a range of school, community, state, and other influences in affecting adolescent substance use and related outcomes. BTG's early research on adolescent diet, physical activity, and obesity--much of which is contained in this supplement--similarly demonstrates the role of environmental factors in influencing these outcomes and in explaining observed racial/ethnic and socioeconomic-related disparities in them.
  
  
  CONCLUSIONS
  The growing recognition of the public health and economic consequences of childhood, adolescent, and adult obesity has led to a variety of policies, programs, and other interventions to stimulate healthy eating and physical activity, often despite the lack of evidence on their impact. BTG and others are working to build the evidence base for effective interventions to address this significant problem, but much remains to be learned.
authors: Department of Economics and Institute for Health Research and Policy, University of Illinois at Chicago, Chicago, Illinois 60608, USA. fjc@uic.edu
authors: Frank J
authors: FJ
authors: Chaloupka
authors: Lloyd D
authors: LD
authors: Johnston
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D035841:Behavioral Research; D002648:Child; D003299:Cooperative Behavior; D015444:Exercise; D015438:Health Behavior; D006291:Health Policy; D006801:Humans; D009765:Obesity / Q000191:economics / Q000209:etiology / Q000517:prevention & control; D015980:Public Health Practice; D012574:Schools; D012927:Social Control, Informal; D019966:Substance-Related Disorders / Q000191:economics / Q000209:etiology / Q000517:prevention & control; D014481:United States