This chapter indicates the evidence for widespread discrimination against obese people in modern developed societies, and note some debates about appropriate language. It highlights some distinctive features of obesity as a ground of discrimination. Most importantly, weight bias is still widely acceptable, and its justifications find institutional support insofar as medicine stresses that obesity is bad and, perhaps, remediable. The chapter argues that the standard rationalisations are untenable, and not only because their factual premises are so dubious. Philosophically, they rest on illiberal confusions about the appropriate place for personal judgments. Discrimination on the grounds of a person's body weight, or more specifically, the amount of body fat he or she is perceived to carry, is ubiquitous in modern Western societies. Obesity provides one of the clearest examples of discrimination on the grounds of individual bodily features. Obesity might be considered naturally discriminatory, so to speak. Human physiology means that body fat has adverse implications for health.