What are the dietary restrictions for patients with kidney disease?

Dietary Restrictions for Patients with Chronic Kidney Disease

Patients with chronic kidney disease should adopt a plant-dominant diet with moderate protein restriction (0.8 g/kg/day for adults with CKD G3-G5), limited sodium intake (<2g/day), and reduced consumption of ultra-processed foods. 1

Protein Intake Management

Adults with CKD

• Maintain protein intake at 0.8 g/kg body weight/day for adults with CKD G3-G5 2, 1
• Avoid high protein intake (>1.3 g/kg/day) in adults at risk of CKD progression 2, 1
• For patients at high risk of kidney failure, consider:
  • Very low protein diet (0.3-0.4 g/kg/day) with essential amino acid or ketoacid supplementation
  • Only under close supervision
  • Only for patients who are willing and metabolically stable 2, 1

Special Populations

• Children with CKD: Do NOT restrict protein due to growth impairment risk; target the upper end of normal range 2, 1
• Older adults with frailty/sarcopenia: Consider higher protein and calorie targets 2, 1
• Metabolically unstable patients: Do NOT prescribe low/very low protein diets 2, 1

Sodium Intake Management

• Limit sodium to <2g/day (<5g sodium chloride/day) 2, 1
• Exception: Sodium restriction is not appropriate for patients with sodium-wasting nephropathy 2, 1
• For children with blood pressure >90th percentile, follow age-based Recommended Daily Intake 2, 1

Dietary Composition

• Emphasize plant-based foods over animal-based foods 2, 1
  • Plant-dominant low-protein diet (PLADO) with at least 50% plant-based sources offers several benefits 3, 4, 5:
    • Reduces uremic toxin production through increased fiber intake
    • Helps correct metabolic acidosis and hyperphosphatemia
    • Less likely to induce glomerular hyperfiltration compared to animal proteins
• Minimize ultra-processed foods 2, 1

Phosphorus Management

• Monitor and control serum phosphorus levels, especially in end-stage renal disease 6
• Phosphate binders like calcium acetate may be prescribed for hyperphosphatemia in ESRD 6
• Plant-based diets naturally help manage phosphorus levels 5

Implementation Approach

Nutritional Assessment and Monitoring

• Refer patients to renal dietitians for individualized dietary education 2, 1
• Focus education on sodium, phosphorus, potassium, and protein modifications 1
• Conduct biannual nutrition screening for all CKD patients 1
• Monitor:
  • Serum albumin levels as a marker of nutritional status
  • Body weight to detect protein loss
  • Renal function and proteinuria regularly 1

Avoiding Complications

• Protein-Energy Wasting: Ensure adequate energy intake (30-35 kcal/kg/day) to maintain nitrogen balance 1, 3, 7
• Hypercalcemia: When using calcium-based phosphate binders, monitor calcium levels to avoid hypercalcemia 6
• Hyperkalemia: Plant-dominant diets may help alleviate constipation, potentially reducing hyperkalemia risk 3

Common Pitfalls and Caveats

1. Overly restrictive diets can lead to malnutrition and protein-energy wasting, which carries mortality risk 1, 8

   • Solution: Regular nutritional assessment and ensuring adequate caloric intake

2. Poor adherence to protein restriction is common 7

   • Solution: Individualized approach with dietitian support and patient preference consideration

3. Ignoring the source of protein when focusing only on quantity 4, 5

   • Solution: Emphasize plant-based protein sources while maintaining adequate nutrition

4. Concurrent use of calcium supplements with calcium-based phosphate binders can lead to hypercalcemia 6

   • Solution: Avoid calcium supplements and monitor calcium levels regularly

5. Neglecting dietary approach as a core treatment rather than just an option 8

   • Solution: Approach dietary management with the same rigor as medication prescription

By implementing these dietary modifications, CKD progression can be slowed, uremic symptoms reduced, and the need for dialysis potentially delayed, ultimately improving patient morbidity, mortality, and quality of life.