The United States has declared a war on fat. I examine this campaign as a biopolitical field of science and governance that has emerged to manage the “obesity epidemic” by remaking overweight and obese subjects into thin, fit, proper Americans. Drawing on research in Southern California, I examine the impact of the campaign on the bodies, selves, and lives of the heavyset young people who are its main targets. At least in this corner of the country, I argue, the war on fat, far from alleviating the problem of fatness, is creating a new fat problem by expanding the number of weight-obsessed, self-identified “abnormal”“fat subjects,” who may not be technically obese but whose desperate efforts to lower their weight endanger their health and bring intense socioemotional suffering. These developments have implications for larger issues of social suffering and social justice.