What dietary considerations should be taken into account for patients with Chronic Kidney Disease (CKD) to manage disease progression and reduce complications?

Dietary Considerations in Renal Patients

Protein Intake Recommendations

For patients with non-dialysis-dependent CKD stage 3 or higher, target dietary protein intake at 0.8 g/kg body weight per day (the recommended daily allowance). 1 This level slows GFR decline with evidence of greater effect over time, while avoiding the risks of more severe protein restriction. 1

• Avoid high protein intake (≥1.3 g/kg/day), as this accelerates albuminuria, kidney function loss, and cardiovascular mortality. 1, 2

• Do not routinely restrict protein below 0.8 g/kg/day unless specific conditions are met: well-nourished patient, informed consent about risks/benefits, resources to comply, and access to expert dietitian supervision. 1 Very low-protein diets (0.3 g/kg/day) have been associated with increased mortality risk (HR 1.92; 95% CI 1.15-3.20). 1

• For dialysis patients, increase protein intake to 1.0-1.2 g/kg/day to prevent protein-energy wasting, which is a major problem in this population. 1

• At least 50% of dietary protein should be of high biological value to maintain nutritional status. 1

Sodium Restriction

Limit sodium intake to <2 g/day to reduce blood pressure and slow CKD progression. 2, 3 This restriction improves blood pressure control and reduces proteinuria. 3

Plant-Based Dietary Patterns

Adopt plant-based predominant diets (such as Mediterranean or DASH diets) with reduced ultraprocessed food consumption. 1, 2 These dietary patterns provide multiple benefits:

• Reduce cardiovascular events and CKD progression risk 1, 2
• Improve gut dysbiosis by reducing pathobionts and protein-fermenting species, decreasing uremic toxin production 4, 5, 6
• Neutralize metabolic acidosis (meat and refined cereals increase dietary acid load) 5, 6
• Lower phosphorus bioavailability compared to animal protein, reducing hyperphosphatemia 5, 6
• Provide adequate magnesium and vitamin K, preventing common deficiencies in CKD 5

Phosphorus Management

Plant-based phosphorus has lower bioavailability than animal phosphorus, enabling better control of hyperphosphatemia. 6 Monitor serum calcium and phosphate levels regularly, particularly in stage 3 CKD and higher. 1

• Maintain serum calcium-phosphorus (Ca x P) product below 55 mg²/dL². 7

Potassium Considerations

Do not routinely restrict plant foods to prevent hyperkalemia unless individualized assessment indicates necessity. 6 The traditional paradigm of limiting fruits and vegetables due to potassium content is outdated. 5

• Plant-dominant diets may actually reduce hyperkalemia risk through improved gut motility and reduced constipation. 4
• Use appropriate cooking techniques (boiling, soaking) to minimize potassium content when needed. 5

Energy Intake

Ensure adequate caloric intake of approximately 35 kcal/kg/day when implementing protein restriction to maintain nutritional status and prevent protein-energy wasting. 1 Inadequate energy intake with protein restriction increases malnutrition risk.

Metabolic Acidosis Management

Plant-based diets neutralize metabolic acidosis, which must be avoided when implementing protein restriction. 1, 5 Metabolic acidosis aggravates CKD progression and should be monitored through serum electrolytes. 1

Glycemic Control for Diabetic Kidney Disease

Target hemoglobin A1c of approximately 7.0% (53 mmol/mol) to prevent or delay progression of diabetic kidney disease. 1, 3 Intensive glycemic control delays onset and progression of albuminuria and reduced eGFR. 1

Nutritional Monitoring

Refer all CKD patients to renal dietitians or accredited nutrition providers for individualized medical nutrition therapy addressing sodium, phosphorus, potassium, and protein intake. 2 This is essential to prevent malnutrition while implementing dietary restrictions.

• Monitor nutritional status periodically under dietitian supervision to avoid protein-energy wasting. 1, 2
• Assess dietary intake through interviews/diaries and normalized protein nitrogen appearance (nPNA). 1
• Monitor serum albumin, body weight, and subjective global assessment (SGA) as nutritional markers. 1

Common Pitfalls to Avoid

Never restrict protein without proper nutritional counseling, as this risks malnutrition and protein-energy wasting. 2 The focus should be on overall diet quality, not solely protein restriction. 2

Do not combine ACE inhibitor with ARB therapy for CKD management—insufficient evidence for benefit with increased harm risk. 3

Avoid calcium supplements and calcium-based antacids when managing hyperphosphatemia, as these increase hypercalcemia risk. 7