<P>One of the most effective ways to improve health and quality of life lies not only in developing new medical approaches but in addressing the causes of harmful personal behaviors. These behaviors—which include tobacco, alcohol, and drug use, poor diet, and physical inactivity—are known risk factors that lead to disease, disability, and death worldwide. </P><P> <I>Health Behavior Change in Populations</I> is designed to teach intermediate and advanced undergraduate students, graduate students, and practitioners the strategic principles and methods for creating positive behavioral change on a population level. With an emphasis on the application of theory and research to practice—and grounded in the ecological model of health behavior change—this core textbook presents current and future public health professionals with a variety of tools for helping people make healthful choices. It also teaches readers strategies for encouraging individuals to participate in community efforts that modify surroundings and circumstances to support actions conducive to health.</P><P>Written and edited by experts in the health professions, the book also addresses the magnitude of current public health challenges. In addition to identifying evidence-based interventions and best practices, the contributors offer guidance for reaching out to diverse communities, explain how social influences affect behavioral choice, and clarify support roles for key stakeholders, including insurers, employers, policymakers, community groups, clinicians, and health departments.</P>