Abstract The American Cancer Society (ACS) publishes nutrition and exercise guidelines as guidelines for its external communications, policy, community strategies, and ultimately to guide dietary and exercise patterns of the American public. The ACS publishes nutrition and exercise guidelines approximately every 5 years, developed by a national panel of experts in the fields of cancer research, prevention, epidemiology, public health, and policy. The nutrition and exercise guidelines incorporate the latest scientific evidence on the association of current dietary and exercise patterns with cancer risk. The American Cancer Society guidelines provide recommendations related to dietary and exercise patterns primarily for individuals in the context of communities that either promote, or impede, these health behaviors. Therefore, the Society also provides a companion set of four individual recommendations related to community action to reduce cancer risk. The Community Action recommendations consider a supportive social and exercise environment to be an essential prerequisite for achieving real opportunities for people from all segments of society to engage in healthy behaviors. The American Cancer Society guidelines are consistent with the guidelines for coronary heart disease and diabetes prevention developed by the American Heart Association and the American Diabetes Association, as well as the general health improvement recommendations set forth in the 2010 edition of the U.S. Dietary Guidelines and the 2008 edition of the U.S. Exercise Guidelines. ca Clin Cancer J 2012;62:30C67.2012 American Cancer Society. 1, Associate Director, Etiology and Prevention Research Group, Department of Research, Kaiser Permanente Medical Center, Oakland, CA; 2, Director, Nutrition and Exercise Group, Division of Cancer Control Sciences, American Cancer Society, Atlanta, GA; 3, Strategic Director, Division of Nutritional Epidemiology, American Cancer Society, Atlanta, GA; 4, Professor, Division of Family and Prevention, University of California, San Diego School of Medicine, San Diego, CA Professor, Division of Medicine; 5, Professor of Nutritional Sciences and Webb Professor Emeritus, University of Alabama at Birmingham, Birmingham, Alabama; 6, Assistant Professor, Cancer Institute of New Jersey, New Brunswick, New Jersey; 7, Associate Professor, Epidemiology Research Program, American Cancer Society, Atlanta, Georgia; 8, Strategic Director, Cancer Prevention Research-3, American Cancer Society, Atlanta, Georgia; 9 Assistant Research Fellow, American Cancer Society, Atlanta, Georgia; 10. Director of Medical Content, American Cancer Society, Atlanta, Georgia.