Coupled with the obesity epidemic, food insecurity presents a public health and social crisis. The United States' industrialized food system embodies an unsustainable network of production and unequal distribution of food creating threats to both the natural environment and human development. Ecological, economic, and social systems are interdependent and their relationships to food security are complex and dynamic. Social workers have a unique set of community practice knowledge and skills that can help communities achieve greater access to affordable, healthy food. Building interdisciplinary networks to change food policies and develop sustainable and equitable food systems can address food insecurity.