Dietary Interventions and Chronic Kidney Disease Progression: A Critical Review of Biomarkers and Clinical Outcomes

Abstract

Nutritional management is a key aspect of chronic kidney disease (CKD) care, with mixed evidence suggesting that dietary modulation may influence renal progression, metabolic issues, and cardiovascular outcomes in context-dependent ways. Contemporary studies highlight the challenges in tailoring macronutrients and micronutrients across CKD stages, where benefits often fail to materialize beyond surrogates like eGFR slope. Protein intake requires balancing potentially restricted in pre-dialysis CKD to reduce uremic toxins (though with risks of malnutrition), and increased in dialysis to counter losses (with limited hard-endpoint data). Sodium reduction may support blood pressure control and renoprotective drugs, but effects on progression are modest and BP-dependent. Potassium strategies aim to retain plant-based benefits without hyperkalaemia, yet evidence is preliminary. Phosphorus management focuses on additives and plant sources to limit CKD-mineral bone disorder, but clinical outcomes remain understudied. Energy adequacy prevents wasting, and acidosis correction via alkali or base-producing foods shows preliminary signals in slowing decline, though superiority over usual care is not consistently demonstrated. Trials indicate very-low-protein diets with ketoanalogues may delay kidney replacement therapy (KRT) in adherent patients (HR 0.36, 95% CI 0.17-0.77 in select trials), but neutral results predominate in broader settings; dietary alkali offers alternatives to bicarbonate, and fiber may reduce toxins without proven clinical impact. Plant-dominant low-protein diets (PLADO) integrate these but face adherence barriers. This review evaluates evidence gaps and mixed findings, emphasizing where anticipated benefits do not hold and implementation fails. Collectively, these insights suggest individualized nutrition as an adjunct with potential, but not guaranteed to influence outcomes, warranting caution against over-optimism.