Ross C. Brownson, PhD, is a professor of epidemiology at Washington University and co-director of the PRC-StL. He has a background in chronic disease epidemiology and brings extensive experience to Project GUIA in the design, implementation, and evaluation of physical activity interventions; implementation of large population-based surveys; implementation research; and translation of science into public health practice in the US and in Latin America. Dr. Brownson has led several large intervention projects addressing physical inactivity, unhealthy eating, and other chronic disease risk factors. He was part of early efforts to better understand the relationships between environmental and policy interventions and tobacco use, physical inactivity, and poor nutrition. This work has helped in developing new intervention approaches among public health practitioners. Dr. Brownson has published over 240 peer-reviewed articles and 6 books, including the first comprehensive text on multilevel obesity prevention. His work on physical activity and health includes etiologic research, qualitative studies, correlates research, and evaluation of community-wide interventions. He was a founding member of the Task Force developing the Community Guide, an important tool for Project GUIA. Dr. Brownson is the principal investigator for Project GUIA. He was also one of the first authors to describe the concepts and framework for evidence-based public health, including the first book on the topic. In 2003, Dr. Brownson was awarded the Abraham Lilienfeld Award from the American Public Health Association for outstanding contributions in teaching and mentoring. He also received the Award for Excellence in Prevention Research and Research Translation in Chronic Disease, from the CDC. Dr. Brownson was recently noted as one of the most productive (English-language) scientists in the world for public health and health promotion research. He has been a member of three Institute of Medicine Committees (including a current committee) addressing prevention of obesity.