It is not true that the idea of the right to subsistence should not give rise to much controversy. In fact, social rights are not considered as fundamental rights by everyone. The aim of this paper is to analyze whether abstract social rights –and the right to subsistence in particular- should be put in constitutions and laws and if judges should be given powers to interpret them. The philosophical foundations and the content of the right are studied and five great challenges are presented, although the most powerful one is to focus on the social and political enforceability of the fundamental right to subsistence. Assessing the effectiveness of the right to subsistence, and the right to food particularly, is a complex issue. In the legal discourse, the question seems to be only suggested. Even when the Constitutions expressly recognize this right in some countries, its implementation faces many constraints. The progressive realization of ESC rights requires a complex interaction of policies and programs in a wide range of sectors and institutions.The scientific method used in this work is the legal-sociological method, regarding the understanding of the rules, the lack of them, their effectiveness, etc. Several methodological techniques have been used, such as social and legal analysis, legal deduction and induction, description and interdisciplinarity.