In the UK, food poverty has been associated with conditions such as obesity, malnutrition, hypertension, iron deficiency, and impaired liver function. Food banks, the primary response to food poverty on the ground, typically rely on community referral and distribution systems that involve health and social care professionals and local authority public health teams. The perspectives of these key stakeholders remain underexplored. This paper reports on a qualitative study of the health and wellbeing challenges of food poverty and food banking in London. An ethnographic investigation of food bank staff and users was carried out alongside a series of healthcare stakeholder interviews. A total of 42 participants were interviewed. A Critical Grounded Theory (CGT) analysis revealed that contemporary lived experiences of food poverty are embedded within and symptomatic of extreme marginalisation, which in turn impacts upon health. Specifically, food poverty was conceptualised by participants to: firstly, be a barrier to providing adequate care and nutrition for young children; secondly, be exacerbated by lack of access to adequate fresh food, food storage and cooking facilities; and thirdly, amplify existing health and social problems. Further investigation of the local government structures and professional roles that both rely upon and serve to further embed the food banking system is necessary in order to understand the politics of changing welfare landscapes.