At one end, family farming is seen as important for incentivizing local ­development. At another end, the Brazilian National School Feeding Program (PNAE) is a social assistance policy that provides food and nutrition for students enrolled in public schools. In 2015, the program fed 41.5 million students across the country. In 2009, these two worlds – family farming and school feeding – were connected through a public policy implemented by law. This law defines that 30% of the financial resources for the acquisition of school feeding, transferred by the federal government to states and municipalities, must be spent on items produced by family farming. However, even considering the legal requirement and many of the changes it has brought, many municipalities still do not meet this minimum requirement. In 2015, more than half of the 5,570 Brazilian municipalities, about 54%, did not reach the 30% minimum; that is, over 3,000 municipalities failed to meet that legal threshold. This context raises some questions: Why is the law not effective? What are the social structures that hinder the implementation of this public policy as it was conceived? One of the theoretical frameworks that could sustain such questioning is Structuration Theory (ST; Giddens, 2003). It brings the concept of structure duality, stating that there is no prevalence between social structure and human action, but rather a reciprocity. In this theory, the structure can be distinguished into three dimensions (signification, domination, and legitimation) and the interaction of these dimensions can lead to either transformation or continuity. Using the lenses of ST, our aim is to identify, analyze, and understand the reverberations of this public policy on social practices and how these reverberations could explain this state of things. For this, we conducted a preliminary field research, based on interviews with key agents involved in the school feeding program in a municipality in the Midwest of Brazil. The preliminary results revealed that the change induced by the law reflected on those agents, altering social practices. New procedures were adopted that transformed social practices pertaining to the dimension of signification. Nevertheless, challenges related to logistics (transport and storage), trust, training, and bureaucracy are still hindering the effectiveness of the intended public policy. As a limitation, we were not under conditions to grasp the changes while they occurred because our point of attention is the scenario after the enforcement of the relevant Law. Beyond that, our study uses ST to deal with the resistance of social structures to change even in a scenario of mandatory law enforcement.