This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book offers theoretical "building blocks" for understanding the interrelations between body, fatness, gender and neoliberalism. It discusses the concepts of neoliberalism, Foucault's concept of governmentality, and neoliberalism as governmentality. The book examines the medicalisation of fatness and presents how the medicalisation of fatness and a neoliberal approach to health seem to complement each other, or at least work in conjunction. It explores the transition from public welfare state healthcare to a neoliberal understanding of health and its consequences. The book addresses the concept of "healthism", which sees health as the primary constituent of an individual's well-being, and as something which should be present in all the choices one makes. It illustrates how health and morals become tangled up with one another in the public discussion on fatness due to the obesity epidemic discourse.