This paper introduces the concept of 'food democracy' as a theoretical framing for HCI to engage in human-food interaction. Extending existing foci of health and environmental sustainability, food democracy requires thinking through aspects of social and economic justice, and democratic governance as directions for the study and design of technologies for alternative food movements. To exemplify food democracy, we report on field observations and interviews about the opportunities and challenges for supporting the development of local food networks with communities in deprived neighbourhoods using an online direct food marketing platform. Using a food democracy framing, we identify tensions around environmental, social, and economic goals; challenges of local food businesses operating within the existing economic paradigm; and differing perspectives on ownership and governance in the network. We discuss the need for HCI to design for systems change and propose a design space for HCI in supporting food democracy movements. © 2018 Copyright is held by the owner/author(s).