The breastfeeding body is a site of complex, contested, and conspicuously moralised practices that has long been a focus for research in the social sciences through to the arts and humanities. Often too the maternal, lactating body is situated within a biomedical frame that marks the milk-producing body as problematic, failing, and subject to and object of expert knowledges. In this frame, women who identify as producing "not enough milk" to feed their babies have been a significant focus.Despite this extensive attention, however, there is little research that has explored women's experiences of and body practices enacted in relation to continued breastfeeding alongside ongoing milk insufficiency, nor the act of milk sharing as a specific response to this bodily insufficiency.In this thesis, I describe and discuss my research with 13 women who have faced difficulties in breastfeeding based on a shared experience of 'chronic milk insufficiency'. I also focus on the act of milk sharing as one response to this insufficiency. Through analysis and discussion of in-depth interviews and observation, I explore how women enact and experience body practices at the intersection of breastfeeding, milk insufficiency, and milk sharing.My critical exploration of breastfeeding, milk insufficiency, and milk sharing as interrelated body practices and modes of meaning-making is informed by, and also informs, the use of a conceptual frame developed through articulation with corporeal and post-constructionist feminism, and ideas from Deleuze and Guattari's work such as deterritorialisation, complex assemblages, flows, desire, and (inter)corporeality. I employ this rhizomatic, cyborg conceptual frame to analyse women's body practices with reference to a number of Deleuzo-Guattarian thematic strands including expectations and beginnings, incorporation and avoidance, the fragmenting body and complex assemblages, creative corporeality and body extension, and becoming-(breastfeeding-)woman.In situating embodied knowledge relative to creative body practices, and highlighting the spaces between bodies and the tension between normative and resistive body practices, I disarticulate and reterritorialise a range of ideas about maternal, lactating bodies. Taken together, these support the conceptualisation of continued breastfeeding in the context of ongoing insufficient milk as a creative, resistant (inter)corporeal act. I further discuss this creative (inter)corporeality in terms of its pragmatic and conceptual implications for anthropologists and social scientists more broadly, as well as for health professionals and others working with pregnant and breastfeeding women.ii Declaration by authorThis thesis is composed of my original work, and contains no material previously published or written by another person except where due reference has been made in the text. I have clearly stated the contribution by others to jointly-authored works that I have included in my thesis.