This article responds to Euro-western conceptions of childhood obesity that understand fat within developmental narratives, as biochemically consequential and as a marker of individualized responsibility. Drawing in multiple fat(s) generated in a pedagogical inquiry with early childhood educators and children, the author articulates 'post-developmental fat(s)' as fat(s) that trouble the logics, practices and relationships required to understand fat as obesity. She traces how situated methods of tending fat(s) generated specific possibilities for counting and fitting fat(s). Foregrounding questions of how fat(s) happen and what fat(s) can do in early childhood education, the author takes seriously how fat(s) matter momentarily amid intentional, speculative and deeply politicized pedagogical practices oriented towards doing fat(s) differently in early childhood education.