Social migration affects the development of rural territories in multiple ways, as it poses a threat to food security and hinders the achievement of sustainable development objectives. The purpose of this research is to represent peasant migration and measure its impact on food security, since it creates conditions that alter people’s access to healthy food. Our research question is: What variables can be used to measure the impact of peasant migration on food security? A three-stage model is implemented, which includes (i) the acquisition of knowledge, (ii) the representation of knowledge, and (iii) decision-making. These stages are the basis of the methodology developed by the ARCOSES research group (Méndez A. System Dynamics and Social Problems. Bogotá: Universidad Distrital Francisco José de Caldas, 2012). The model developed to represent peasant migration and its impact on food security has five components. The model representation was applied in 58 typical rural municipalities, observing a potential loss of 30,580,000 tons of food, which amounts to 5% of the national production. Likewise, it was observed that 70% of migrating farmers are part of the economically active population. Colombian governorships should strive towards a greater and more comprehensive development of rural municipalities in order to avoid massive displacement to urban regions, which affects the availability of rural labor, causes poor agricultural production levels and compromises food sustainability. To ensure peasants’ full access to food and their well-being, an assertive intervention should be carried out by the Colombian State.