This paper explores 'being fat' in terms of three contrasting models of disability. First, the medical model with its predisposition for ever increasing pathology, secondly the social model formed from a political movement of disabled people and finally the affirmation model with its reinforcement of positive disability identities. In utilising these models the general question of whether being fat should be regarded as a disability and/or impairment is explored. This in turn poses fundamental questions concerning the theoretical nature of disability itself. The critical role of both disability legislation and discrimination are examined along with a post modern analysis of what appears to be a moral panic over weight gain. The paper draws upon research and other writing to propose that both being fat and disability are complex social phenomena requiring further cross theorising.