Every country has populations that are affected by malnutrition, and one third of all people in the world are malnourished. Among approaches to addressing malnutrition, the language of human rights is notably present in international nutrition discourse and national policy and covenants, but the conceptualization, implications and utility of human rights for nutrition practice are contested.This empirical research explores how the utility of a ‘right to nutrition’ is perceived by different actors, and how differences in interpretation affect its potential for reducing malnutrition. In undertaking this qualitative case-study, we apply socio-legal, critical development studies, and political science approaches to compare and contrast written documents and stated viewpoints, across actors in different sectors and levels from global to local, with a focus on Zambia.Human rights are clearly integrated with ideas of nutrition in written documents across levels, but these are largely rhetorical devices providing moral leverage and guiding language, not clearly directing action. Zambia has domesticated relevant international human rights law and has recent case law implicitly underpinning a right to nutrition; using the law brings a strengthening of policy, but also a narrowing of focus in terms of populations covered and issues justiciable. Views on what a right to nutrition means in practice are contested, with a lack of citizen’s rights education limiting participation, and a lack of clear norms on who should be doing what scattering accountability.Our research demonstrates that there are three distinct aspects to a rights-based approach—rhetorical, legal and practical—but that these generally act in silos. We argue that explicitly acknowledging these three functions of human rights is an important first step if a right to nutrition is desired; and explicitly addressing these aspects in combination and in context is fundamental to a coherent rights-based approach to nutrition.