Recommended Diet for Individuals with Proteinuria
For individuals with proteinuria, a protein-restricted diet of 0.8 g/kg body weight per day (the Recommended Dietary Allowance) is strongly recommended to reduce proteinuria and slow progression of kidney disease. 1
Protein Recommendations
- Target protein intake should be 0.8 g/kg body weight per day for individuals with proteinuria and chronic kidney disease (CKD) stages 1-4 1
- For individuals who cannot maintain adequate caloric intake with this level of protein restriction, intake up to 0.75 g/kg/day may be prescribed 1
- At least 50% of dietary protein should be of high biological value (complete proteins containing all essential amino acids) 1
- High-protein diets (>20% of total calories from protein) should be strictly avoided as they increase albuminuria and may accelerate loss of kidney function 1
Mechanism and Benefits of Protein Restriction
- Protein restriction reduces glomerular hyperfiltration and intraglomerular pressure, which are mechanisms of kidney damage induced by excess dietary protein 1
- Studies show that even modest protein restriction (0.89 vs 1.02 g/kg/day) substantially reduced the risk of end-stage kidney disease or death (RR 0.23) in people with diabetes and CKD 1
- Meta-analyses demonstrate that low-protein diets reduce risks of:
- Loss of kidney function (measured by GFR decline)
- Increased albuminuria/proteinuria
- Progression to end-stage kidney disease 1
- Recent research shows low protein diet can decrease proteinuria up to 47% within 3 months 2
Protein Quality and Sources
- Consider replacing some animal protein with plant protein sources 1
- Some studies suggest beneficial effects from plant protein compared to animal protein in reducing proteinuria 1
- When using plant proteins, ensure adequate essential amino acid intake through variety 1
Additional Dietary Recommendations
- Maintain adequate caloric intake (approximately 35 kcal/kg/day) when restricting protein to prevent malnutrition 1
- Limit saturated fatty acids and trans-unsaturated fatty acids to <10% (and preferably <7%) of energy intake 1
- Consider incorporating monounsaturated fats which may be beneficial for those with metabolic syndrome 1
- Limit sodium consumption to <2,300 mg/day 1
- For individuals with elevated triglycerides, consider supplementation with fish oils containing omega-3 fatty acids 1
Special Considerations
- Protein restriction appears more beneficial in type 1 diabetes than type 2 diabetes, though fewer studies have been conducted in type 2 diabetes 1
- For individuals with very advanced CKD (GFR <25 mL/min) who are not on dialysis, a more restricted protein intake of 0.6 g/kg/day may be considered 1
- The diet for diabetes and CKD is complex and requires management of multiple nutrients (protein, carbohydrates, fat, sodium, potassium, phosphate) 1
- Avoid high-protein/low-carbohydrate diets which are particularly risky for patients with diabetes as they can accelerate progression of diabetic kidney disease 1
Monitoring and Implementation
- Nutritional intervention should be implemented by personnel with expertise in dietary management 1
- Monitor nutritional status regularly to prevent malnutrition 1
- Measure proteinuria at 3 months after starting dietary intervention to assess response - a reduction >50% in proteinuria at 3 months predicts better outcomes 2
- Combine dietary protein restriction with conventional nephroprotective therapy (ACE inhibitors, blood pressure control) for optimal results 1, 3
By following these dietary recommendations, individuals with proteinuria can potentially slow the progression of kidney disease, reduce proteinuria, and delay the need for kidney replacement therapy.