What are the dietary recommendations for patients with Chronic Kidney Disease (CKD)?

Dietary Recommendations for Chronic Kidney Disease

For patients with CKD stages 3-5 not on dialysis, maintain protein intake at 0.8 g/kg body weight per day, ensure energy intake of 30-35 kcal/kg/day (or 35 kcal/kg/day if under 60 years), restrict sodium to less than 2 g/day, limit phosphorus intake, and emphasize a plant-based dietary pattern. 1, 2

Protein Management

Standard Protein Targets by CKD Stage

• CKD stages 1-4 (GFR >15 mL/min): Target 0.8 g/kg/day, which represents the recommended daily allowance and has been shown to slow GFR decline with evidence of greater effect over time 1, 3, 2

• CKD stage 5 (GFR <15 mL/min, not on dialysis): Target 0.6-0.8 g/kg/day to slow progression and minimize uremic toxin accumulation while maintaining nutritional status 1, 4, 5

• Avoid high protein intake (>1.3 g/kg/day or >20% of daily calories): This level is associated with increased albuminuria, accelerated kidney function loss, and increased cardiovascular mortality 1, 3

Very Low-Protein Diet Option

• For metabolically stable patients at high risk of kidney failure progression who are willing and able, consider a very low-protein diet of 0.3-0.4 g/kg/day supplemented with essential amino acids or ketoacid analogs (total up to 0.6 g/kg/day) under close dietitian supervision 4, 3, 2

• Critical caveat: Never prescribe low or very low-protein diets in metabolically unstable patients, as this significantly increases malnutrition risk 4, 3

Energy Requirements

• Patients under 60 years: 35 kcal/kg/day to maintain neutral nitrogen balance, promote normal serum albumin, and improve protein utilization 1, 2

• Patients 60 years or older: 30-35 kcal/kg/day, accounting for reduced physical activity in this age group 1, 2

• Adequate energy intake is essential to prevent protein-energy wasting and maintain nutritional status during protein restriction 1, 5

Sodium Restriction

• Limit sodium to less than 2 g/day (or <2,300 mg/day) for all CKD patients to control blood pressure, reduce volume overload, and decrease cardiovascular risk 2, 1

Phosphorus Management

• Begin dietary phosphorus restriction when GFR falls below 60 mL/min/1.73 m² (stage 3 CKD) or when serum phosphorus becomes elevated 1

• Target phosphorus intake should be as low as possible while ensuring adequate protein intake, estimated at 10-12 mg phosphorus per gram of protein consumed 1

• Select protein sources with the lowest phosphorus content to achieve restriction without compromising protein adequacy 1

• If phosphorus or intact PTH levels cannot be controlled despite dietary restriction, add phosphate binders 1

Dietary Pattern Emphasis

• Prioritize plant-based foods: Emphasize vegetables, fruits, whole grains, fiber, legumes, plant-based proteins, unsaturated fats, and nuts over animal-based proteins 2

• Plant-dominant low-protein diets (>50% plant-based sources) may provide additional benefits including favorable gut microbiome alterations, reduced uremic toxin generation, lower cardiovascular risk, and reduced constipation-related hyperkalemia risk 6

• Minimize ultraprocessed foods 2

Special Populations

Patients on Dialysis

• Hemodialysis: Increase protein to 1.0-1.2 g/kg/day (or 1.2-1.4 g/kg/day per some sources) to offset dialytic losses and catabolism 4, 2

• Peritoneal dialysis: Similarly increase to 1.0-1.2 g/kg/day 4

Older Adults with Frailty or Sarcopenia

• Consider higher protein and calorie targets to prevent muscle wasting, as standard protein restriction may worsen functional status 4, 3

Hospitalized Patients

• Do not continue protein restriction during acute illness hospitalization 3

• For polymorbid medical inpatients with eGFR <30 mL/min not on dialysis, target 0.8 g/kg/day showed the strongest mortality benefit (OR 0.37,95% CI 0.14-0.95) 3

Diabetic Kidney Disease

• Maintain the same protein target of 0.6-0.8 g/kg/day as for non-diabetic CKD, with intensive glycemic control to delay onset and progression of albuminuria 1, 4

Implementation Strategy

Mandatory Dietitian Involvement

• Refer all CKD patients to renal dietitians or accredited nutrition providers for individualized medical nutrition therapy, education about sodium/phosphorus/potassium/protein adaptations, and ongoing monitoring 4, 2

• Studies demonstrating successful nutritional outcomes with protein restriction were conducted with careful dietitian instruction, regular counseling, and close monitoring 1

• Patients "casually" instructed to restrict protein without regular follow-up are at serious risk for malnutrition 1

Body Weight Calculations

• Use adjusted body weight for protein calculations, not fluid-overloaded weight 3

Comprehensive Dietary Approach

• Do not focus solely on protein restriction—simultaneously address sodium, phosphorus, and potassium intake as part of a comprehensive dietary plan 3, 2

Monitoring Requirements

• Frequency: Monitor nutritional status at 1-3 month intervals depending on CKD stage (every 6-12 months for stage 3, every 3-5 months for stage 4, every 1-3 months for stage 5) 1, 2

• Parameters to assess:

  • Appetite assessment and dietary intake evaluation 2
  • Body weight changes and anthropometric measurements 2
  • Biochemical markers including serum albumin, prealbumin, and transferrin 4, 2
  • Muscle function and physical performance (e.g., 6-minute walk distance) 7
  • Plasma leucine levels (values <95.5 μM may herald muscle wasting and malnutrition in CKD stage 3-5 patients with inadequate calorie intake) 7

• Watch for signs of protein-energy wasting, which is associated with increased morbidity and mortality 4, 2

Common Pitfalls to Avoid

• Never implement protein restriction without proper nutritional counseling and regular monitoring, as haphazard restriction leads to malnutrition 1, 4

• Do not reduce protein below 0.8 g/kg/day without renal dietitian supervision, as this significantly increases malnutrition risk 3

• Ensure adequate calorie intake is maintained when restricting protein—most CKD patients (approximately 85%) have inadequate daily calorie intake despite dietary counseling 7

• Monitor for declining hemoglobin, albumin, and functional capacity (such as reduced 6-minute walk distance), which are independently associated with low protein diets when calorie intake is inadequate 7

• Do not prescribe protein restriction to metabolically unstable patients 4, 3