What dietary recommendations are suitable for a patient with impaired renal function?

Dietary Prescription for Renal Patients

For patients with chronic kidney disease (CKD) stages 3-5 not on dialysis, prescribe a protein intake of 0.8 g/kg body weight/day, sodium restriction to <2 g/day (<5 g sodium chloride/day), and energy intake of 30-35 kcal/kg/day, with mandatory referral to a renal dietitian for individualized implementation. 1

Core Macronutrient Targets

Protein Intake by CKD Stage

For CKD G3-G5 (not on dialysis):

• Maintain protein at 0.8 g/kg body weight/day for metabolically stable adults 1, 2, 3
• Avoid high protein intake >1.3 g/kg/day as this accelerates progression and increases albuminuria 1, 2, 3
• For patients at high risk of kidney failure who are willing and able, consider a very low-protein diet (0.3-0.4 g/kg/day) supplemented with essential amino acids or ketoacid analogs under close supervision 1, 2

Critical exception - Do NOT restrict protein in:

• Metabolically unstable patients 1, 2
• Older adults with frailty or sarcopenia (consider higher protein targets) 1, 2
• Hospitalized patients with acute illness 1, 3

For dialysis patients:

• Hemodialysis: Increase to 1.2-1.4 g/kg/day to offset catabolism 1, 4
• Peritoneal dialysis: Increase to 1.5 g/kg/day due to protein losses in dialysate 4

Energy Requirements

Prescribe based on age and activity level:

• Adults <60 years: 35 kcal/kg/day 1
• Adults ≥60 years: 30-35 kcal/kg/day (lower end due to reduced activity) 1
• Use ideal body weight for calculations, not fluid-overloaded weight 3

This energy target is essential to maintain nitrogen balance, prevent protein-energy wasting, and optimize protein utilization 1

Electrolyte and Mineral Management

Sodium Restriction

Target: <2 g sodium/day (equivalent to <90 mmol/day or <5 g sodium chloride/day) 1

This applies to all CKD patients including those with diabetes and hypertension 1

Exception: Do not restrict sodium in patients with salt-wasting nephropathy 1

Phosphorus and Potassium

• Tailor phosphorus and potassium restrictions based on laboratory values and CKD stage 1
• Hemodialysis patients: Limit potassium to <1 mEq/kg/day (approximately 30-50 mEq/day) 4
• Peritoneal dialysis patients: More liberal potassium allowance (2000-3000 mg/day) due to daily dialysis 4

Dietary Pattern Approach

Recommend a plant-based, minimally processed dietary pattern:

• Higher consumption of vegetables, fruits, whole grains, fiber, legumes, plant-based proteins, unsaturated fats, and nuts 1
• Lower consumption of processed meats, refined carbohydrates, and sweetened beverages 1
• Mediterranean diet pattern has demonstrated preventive effects on renal function and slows disease progression 5, 6

This approach addresses multiple cardiovascular risk factors while meeting renal-specific restrictions 1

Physical Activity Integration

Prescribe moderate-intensity physical activity for ≥150 minutes per week 1

Physical activity should be compatible with cardiovascular and physical tolerance, as sedentary behavior is associated with adverse outcomes in CKD 1

Implementation Strategy

Mandatory Referral to Renal Dietitian

All CKD patients require referral to a renal dietitian or accredited nutrition provider 1, 2, 3

The dietitian will:

• Assess baseline nutritional status (BMI, serum albumin, prealbumin, anthropometrics) 1
• Calculate individualized protein, energy, and electrolyte targets 1, 2
• Provide education on reading food labels and meal planning 1
• Monitor adherence and adjust recommendations based on laboratory values 2, 3

Monitoring Parameters

Track these markers regularly:

• Body weight changes and BMI 1
• Serum albumin (target >35 g/L) and prealbumin (target >300 mg/L) 1, 2
• Electrolytes (sodium, potassium, phosphorus) 1, 2
• Signs of protein-energy wasting (muscle loss, cachexia) 2, 5

Critical Pitfalls to Avoid

Do not implement protein restriction without proper nutritional counseling - this significantly increases malnutrition risk, which is a strong predictor of mortality in CKD 2, 3, 5

Do not focus solely on protein restriction - address sodium, phosphorus, and potassium simultaneously, as isolated protein restriction without comprehensive dietary modification is counterproductive 2, 3

Do not use actual body weight for calculations in fluid-overloaded patients - use adjusted or ideal body weight to avoid underfeeding 3

Do not continue protein restriction during acute hospitalization - metabolic demands increase during acute illness, requiring liberalization of protein intake 1, 3

Do not prescribe low-protein diets in children - this causes growth impairment; target protein intake should be at the upper end of normal range 1