Both the United Kingdom and United States are grappling with nationwide epidemics of obesity. Obesity contributes to diabetes, cardiovascular disease, and some cancers, among other diseases. Although many people are aware of obesity’s causes and consequences, few see it as a problem for their own families–despite clinical evidence to the contrary. Given this disconnect between perception and reality, policy makers in both countries struggle to find a way to reach people to encourage change. The IOM brought together policy makers from the U.K. and U.S. for a workshop on October 22, 2009, to discuss the challenges of and promising approaches to the struggle against obesity. Presenters spoke about current policies, programs, and partnerships that are addressing the obesity epidemic and evidence for effective strategies to change perception and behaviors. The workshop, summarized in this document, provided an opportunity for both countries to learn from each other’s efforts and to consider how to apply new strategies at home.