The aim of this paper is to assess the causal impact of trade policy distortions on food security. This is an hot issue since restrictions to agricultural trade have been generally applied by national governments, especially in developing countries, as a tool to insulate domestic markets from international prices turmoil. The added value of this work is twofold: i) the use of a non parametric matching technique with continuous treatment, namely the Generalised Propensity Score (GPS) to address the self selection bias; ii) the analysis of heterogeneity in treatment (by commodities) as well as in outcome (i.e., different dimensions of food security). The outcomes of our estimates show clearly that trade policy distortions are, overall, significantly correlated with the various dimensions of food security under analysis. Specifically, countries supporting the primary sector tend to be better off in all the dimensions of food security (food availability, access, utilisation and stability. However, the maximum level of food security is associated with moderate protection policies.