This article examines the obesity, health, and physical activity discourses of the past 35 years in the context of the United States with particular reference to five social sectors: the biomedical domain; the popular media; nonprofit foundations, centers and agencies; various national and multinational corporations; and government at all levels. These categories were identified as relevant for this project based on their various roles in crafting messages related to health generally, and obesity specifically. These are the domains from which the most influential rhetoric, decisions, and policies originate. Our analysis includes an examination of the ways in which the rhetoric within these domains produces a discourse that supports the view that a public health "crisis" and "epidemic" actually exist. In addition, this specific health discourse provides the basis upon which a variety of health agendas and interventions have been developed and implemented. Although there is considerable evidence of the influence of the Western, and specifically, United States lifestyle on other developed and developing nations, this article only considers the American context. Explication of the impact of the exportation of lifestyle ideas and behavior to other nations deserves further consideration. Finally, we will consider the ways in which practitioners and scholars in the field of Physical Education have reacted to and taken responsibility for obesity among schoolchildren. (Contains 3 notes.)