What is a CKD Diet?
A CKD diet is a comprehensive eating pattern that emphasizes plant-based foods over animal-based foods, restricts protein to 0.8 g/kg body weight/day for stages 3-5, limits sodium to <2 g/day, and requires individualized management of phosphorus and potassium under supervision of a renal dietitian. 1
Core Dietary Components
Protein Management
- Maintain protein intake at 0.8 g/kg body weight/day for adults with CKD stages 3-5 (non-dialysis). 1 This target slows disease progression while preserving nutritional status.
- Avoid high protein intake exceeding 1.3 g/kg body weight/day, as this accelerates kidney function decline and increases albuminuria. 1
- For dialysis patients, protein requirements increase to 1.0-1.2 g/kg/day due to dialytic losses and increased catabolism. 1, 2
- Very low-protein diets (0.3-0.4 g/kg/day) supplemented with essential amino acids or ketoacid analogs may be considered for high-risk patients willing and able to comply, but only under close medical supervision. 1, 2
Sodium Restriction
- Limit sodium intake to <2 g per day (equivalent to <90 mmol/day or <5 g salt/day). 1 This helps control blood pressure and reduces cardiovascular risk.
- Sodium restriction is not appropriate for patients with sodium-wasting nephropathy. 1
Dietary Pattern Emphasis
- Adopt a plant-based dietary pattern with higher consumption of vegetables, fruits, whole grains, legumes, and plant proteins compared to animal-based foods. 1, 3
- Minimize ultraprocessed foods. 1
- Mediterranean-style and DASH (Dietary Approaches to Stop Hypertension) dietary patterns have demonstrated benefits in slowing CKD progression and reducing mortality. 4, 5, 6
Energy Requirements
- Ensure adequate caloric intake of 30-35 kcal/kg body weight/day to prevent protein-energy wasting and maintain nitrogen balance. 3, 7
Special Population Considerations
Older Adults with Frailty or Sarcopenia
- Consider higher protein and calorie targets to prevent muscle wasting, rather than restricting protein. 1, 7
Children with CKD
- Do not restrict protein in children due to risk of growth impairment. Target protein and energy intake should be at the upper end of normal range for healthy children. 1
Metabolically Unstable Patients
- Do not prescribe low or very low-protein diets in metabolically unstable patients, as this significantly increases malnutrition risk. 1, 7
Implementation Strategy
Professional Guidance Required
- Referral to a renal dietitian or accredited nutrition provider is essential for education about dietary adaptations regarding sodium, phosphorus, potassium, and protein intake tailored to CKD severity and comorbidities. 1, 3
- Frequent patient contact with a registered dietitian improves adherence and clinical outcomes. 1
Monitoring Requirements
- Monitor nutritional status at 1-3 month intervals including appetite assessment, dietary intake evaluation, body weight changes, biochemical markers (serum albumin, prealbumin), and anthropometric measurements. 2, 3
- Watch for signs of protein-energy wasting, which is associated with increased morbidity and mortality. 2, 7
Critical Pitfalls to Avoid
- Never implement protein restriction without proper nutritional counseling, as this can lead to malnutrition and worse outcomes. 2, 7
- Do not focus solely on protein restriction while ignoring overall diet quality—sodium, phosphorus, and potassium management are equally important. 2, 7
- Do not continue protein restriction if the patient becomes hospitalized for acute illness, as metabolic demands change. 7
- Use adjusted body weight for protein calculations, not fluid-overloaded weight. 7
Evidence for Clinical Outcomes
- Greater adherence to healthy dietary patterns (Mediterranean, DASH) is associated with 24-31% lower risk for all-cause mortality and 25% lower risk for CKD progression. 4
- Dietary interventions lower systolic blood pressure by approximately 9 mm Hg and diastolic blood pressure by 9 mm Hg. 6
- Dietary modifications increase eGFR and serum albumin levels while lowering serum LDL cholesterol. 6