CKD is defined as a GFR below 60 mL/min/1.73 m² or markers of kidney damage (proteinuria, structural abnormality) persisting for more than three months. The five stages run from mild function loss (Stage 1, GFR ≥ 90) through kidney failure (Stage 5, GFR < 15), which requires dialysis or transplant.
Nutrition management in CKD is one of the most nuanced areas in dietetics — and one where unsupervised changes carry real risk.
Protein is the most debated: a modest restriction (0.6–0.8 g/kg/day) in non-dialysis CKD may slow progression, but too little accelerates muscle wasting. Dialysis patients paradoxically need more protein (1.2–1.4 g/kg/day) to replace dialytic losses. The right amount depends on stage, treatment, and individual factors.
Potassium restriction becomes necessary from Stage 3–4 as kidneys lose the ability to excrete it; hyperkalaemia can cause dangerous heart rhythms. Phosphate (found in dairy, nuts, seeds, processed foods) accumulates and damages blood vessels and bone in advanced CKD. Fluid restriction may be required in later stages.
CKD nutrition is highly individualised and must be guided by a renal dietitian working alongside your nephrologist.