From the Guidelines
High protein intake should be avoided in individuals with chronic kidney disease (CKD) as it can lead to increased albuminuria, more rapid kidney function loss, and cardiovascular disease (CVD) mortality, as evidenced by the 2025 standards of care in diabetes 1. When considering the impact of high protein intake on creatinine levels, it's essential to understand that creatinine is a waste product of muscle tissue breakdown.
- Consuming large amounts of protein can increase creatinine production in the body, potentially leading to elevated creatinine levels in the blood.
- However, the primary concern with high protein intake in CKD patients is not just the temporary elevation of creatinine levels but the potential for long-term kidney damage and increased CVD risk.
- The recommended daily protein intake for individuals with stages 3-5 non-dialysis-dependent CKD is 0.8 g/kg body weight per day, as this level has been shown to slow GFR decline with evidence of a greater effect over time 1.
- Reducing protein intake below the recommended daily allowance of 0.8 g/kg/day is not recommended, as it does not alter blood glucose levels, cardiovascular risk measures, or the course of GFR decline 1. Key considerations for managing CKD include:
- Restricting dietary sodium to <2,300 mg/day to manage blood pressure and reduce cardiovascular risk.
- Individualizing dietary potassium intake to manage serum potassium concentrations, particularly for individuals with reduced eGFR.
- Avoiding high protein intake (>20% of daily calories from protein or >1.3 g/kg/day) to prevent increased albuminuria, kidney function loss, and CVD mortality 1.
From the Research
High Protein Intake and Creatinine Levels
- High protein intake has been suggested to increase creatinine levels, which may be an indicator of kidney function 2, 3, 4, 5.
- Studies have shown that a high-protein diet can cause glomerular hyperfiltration, a potentially maladaptive response, which may accelerate the progression of kidney disease 4, 5.
- The effects of high protein intake on kidney function are still uncertain, and more research is needed to determine the long-term effects of high protein diets on kidney health 2, 3, 4, 5.
Mechanisms of High Protein Intake on Kidney Function
- High dietary protein intake can cause intraglomerular hypertension, which may result in kidney hyperfiltration, glomerular injury, and proteinuria 3.
- The quality of dietary protein may also play a role in kidney health, with animal protein being associated with an increased risk of end-stage kidney disease (ESKD) compared to plant-based protein sources 3.
Clinical Implications
- Screening for kidney disease should be considered before and during long-term, high-protein intake, especially in individuals with preexisting kidney disease or those at high risk for kidney disease 2, 5.
- Serum creatinine is a widely used biomarker of kidney function, but its use has limitations and alternative biomarkers may be needed to accurately assess kidney function 6.