Nutrition and Green Nephrology-not only for health but also for compensation: the water footprint and its hamburger equivalent.

Nutrition is recognized as a cornerstone of chronic kidney disease (CKD) prevention and management, while healthcare sustainability has become a major priority in nephrology. These two challenges converge because dietary choices influence both kidney health and the environmental footprint of care. In this narrative review, enriched by the perspectives of patients who experienced CKD, dialysis, and kidney transplantation, we discuss how nutritional interventions can simultaneously improve clinical outcomes and reduce the carbon and water footprint associated with kidney care. We summarize current evidence supporting healthy plant-dominant dietary patterns across the CKD continuum, from disease prevention to conservative management, dialysis and transplantation. We highlight the emerging shift from nutrient restriction toward food quality, emphasizing minimally processed plant-based foods, moderation of animal protein intake and individualized nutritional counseling. The review also discusses the evolving evidence challenging traditional dietary paradigms in advanced CKD and dialysis, particularly regarding protein, potassium and phosphate management. To illustrate the environmental implications of nutritional choices, we introduce the concept of the "hamburger equivalent," comparing the annual water footprint of hemodiafiltration with that required for beef production. Rather than promoting guilt or restricting the choice of effective kidney replacement therapies, this concept illustrates how healthier dietary habits may help offset part of the unavoidable environmental burden of kidney care. Throughout the CKD journey, personalized nutritional counseling that respects patients' cultural preferences and values may improve adherence, quality of life and clinical outcomes while contributing to planetary health. Integrating sustainable nutrition into routine nephrology practice therefore represents an opportunity to align high-quality patient care with environmental stewardship.