There is a considerable stigma associated with obesity, among healthcare professionals as well as the general population, which often leads to discrimination and weight bias. But why is there a stigma attached to obesity? The origin of this stigma has been identified in the 18th century but its roots lie much further back in history. There is some debate about how this negative perception of obesity arose and the role of medical professionals in its creation. This paper examines both positive and negative conceptions by following three major aspects of the modern stigma through from Palaeolithic statues to the medical texts of ancient Greece and Rome, finishing with the medical and literary sources of the 18th century 'Enlightenment'. The modern perception of obesity originated in the social and scientific climate of the Enlightenment through the combination of three key themes; obesity as conspicuous consumption, associations with suspect morals and excess, and as an outward representation of the soul. The evolution of each of these themes can be clearly identfied in pre-Enlightenment sources. By the eighteenth century, these perceptions became amplified by, and disseminated through, the literary and media boom to create a recognisably modern stigma against the obese.