Nutrition as a missing link in One Health: from conceptual invisibility to strategic action.

The One Health approach recognizes the interdependence between human, animal, and ecosystem health and calls for integrated, system-oriented responses to contemporary health challenges. This viewpoint argues that One Health depends on the coordinated engagement of all health professionals, and that dietitians (also referred to as nutritionists, as the professional title varies across countries) play a particularly strategic role due to the systemic reach of their practice. Operating at the interface of food systems, dietary behaviors, population health, and environmental sustainability, dietitians are well-positioned to address upstream determinants of health across the life course. We highlight how nutrition practice advances One Health objectives, often without being explicitly recognized as One Health action by professionals themselves. We discuss key barriers to conceptual uptake and propose strategies to make nutrition's contribution visible, intentional, and strengthened through education, interprofessional collaboration, research, and evaluation frameworks. Making One Health explicit in nutrition practice is essential to translating the paradigm into sustainable action and addressing interconnected challenges of environmental degradation, health inequities, and long-term population well-being.