The United States, we are told, is facing an obesity epidemic-a "battle of the bulge" of not just national, but global proportions-that requires drastic and immediate action. Experts in the media, medical science, and government alike are scrambling to find answers. What or who is responsible for this fat crisis, and what can we do to stop it? Abigail Saguy argues that these fraught and frantic debates obscure a more important question: How has fatness come to be understood as a public health crisis at all? Why, she asks, has the view of "fat" as a problem-a symptom of immorality, a medical pathology, a public health epidemic-come to dominate more positive framings of weight-as consistent with health, beauty, or a legitimate rights claim-in public discourse? Why are heavy individuals singled out for blame? And what are the consequences of understanding weight in these ways? What's Wrong with Fat? presents each of the various ways in which fat is understood in America today, examining the implications of understanding fatness as a health risk, disease, and epidemic, and revealing why we've come to understand the issue in these terms, despite considerable scientific uncertainty and debate. Saguy shows how debates over the relationship between body size and health risk take place within a larger, though often invisible, contest over whether we should understand fatness as obesity at all. Moreover, she reveals that public discussions of the "obesity crisis" do more harm than good, leading to bullying, weight-based discrimination, and misdiagnoses. Showing that the medical framing of fat is literally making us sick, What's Wrong with Fat? provides a crucial corrective to our society's misplaced obsession with weight.