This paper aims to mobilize the way we think and write about fat bodies while drawing on Jean-Luc Nancy’s philosophy of the body. I introduce Nancy’s approach to the body as an addition to contemporary new materialism. His philosophy, so I argue, offers a form of materialism that allows for a phenomenological exploration of the body. As such, it can help us to understand the lived experiences of fat embodiment. Additionally, Nancy’s idea of the body in terms of a “corpus”—a collection of pieces without a unity—together with his idea of corpus-writing—fragmentary writing, without head and tail—can help us to mobilize fixed meanings of fat. To apply Nancy’s conceptual frame to a concrete manifestation of fat embodiment, I provide a reading of Roxane Gay’s memoir Hunger (2017). In my analysis, I identify how the materiality of fat engenders the meaning of embodiment, and how it shapes how a fat body can and cannot be a body. Moreover, I propose that Gay’s writing style—hesitating and circling – involves an example of corpus-writing. The corpus of corpulence that Gay has created gives voice to the precariousness of a fat body's materialization.