Protein Needs for Renal Failure Patients
Renal disease is a complex condition with multiple nutrition implications. The renal diet is one
of the most complicated for dietitians to teach and for patients to comply with. Protein is one of
the nutrients that is addressed for patients with renal disease. Significant controversy is found in
the literature over appropriate protein restrictions for patients with renal disease. An excellent
overview of the kidneys and associated disease states is available at
http://www.nlm.nih.gov/medlineplus/kidneysandurinarysystem.html.
Many different types of renal failure exist, but this document addresses the protein needs of
individuals with chronic renal failure (CRF) and renal failure with dialysis.
CRF may result from a number of causes of renal dysfunction, although the most common cause
is diabetic nephropathy. It is categorized as diminished renal reserve, renal insufficiency, and
renal failure (end-stage renal disease). Chronic kidney disease is classified into five stages based
on the glomerular filtration rate (GFR):
Stage 1: Normal GFR (>90 mL/minute/1.73m2 and persistent albuminemia
Stage 2: GFR 60−89 mL/minute/1.73 m2
Stage 3: GFR 30−59 mL/minute/1.73 m2
Stage 4: GFR 15−29 mL/minute/1.73 m2
Stage 5: GFR<15 mL/minute/1.73 m2 (hemodialysis required at Stage 5)
GFR=glomerular filtration rate, mL=milliliter, m2=square meters
Glomerular filtration rate is calculated by using the following formulas.
Cockcroft-Gault Equation
Creatinine clearance (mL/minute)=[(140-age)  weight/72  serum creatinine]  (0.85 if female)
MDRD (Modification of Diet in Renal Disease Study)
GFR=170  serum creatinine-0.999  age-0.176  female0.762  (1.18 x black race) x SUN-0.17  serum
albumin0.318
SUN=serum urea nitrogen
Once the stage of renal failure is identified, a practitioner can estimate protein needs. Current
recommendations based on the Academy of Nutrition and Dietetics’ Nutrition Care Manual® for
Stages 1–4 of chronic kidney disease indicate 0.60–0.75 g protein/kilogram (kg) body weight,
≥50% of high biological value (HBV). The rationale for this recommendation is that low-protein
meal plans reduce the amount of nitrogenous wastes and lessen the effects of electrolyte
disorders.
Evidence also shows that low-protein diets slow the progression of renal failure or delay the
onset of dialysis. Some controversy is associated with this theory. However, it is important to
weigh the potential benefits of protein restriction needs against the hazards of malnutrition,
ability to obtain adequate energy intake with protein restrictions, and the patient’s ability to
comply with protein restrictions.
Protein needs during Stage 5 renal failure (dialysis) are increased. Patients undergoing
hemodialysis should have 1.2 g protein/kg body weight, ≥50% HBV. Patients undergoing
peritoneal dialysis should have 1.2–1.3 g protein/kg body weight, ≥50% of HBV. These values
are recommended because of the loss of protein during the dialysis process.
Implications for dietetics practitioners
Protein restriction (0.6 g/kg) is appropriate for those suffering from CRF. Calculating the GFR
can help a dietitian assess the degree of renal failure and provide guidance for an appropriate
protein prescription. Patients undergoing peritoneal or hemodialysis (Stage 5) have higher
protein needs than those with CRF (Stages 1–4). In some cases, protein supplements are
necessary to meet protein needs, especially if a patient has a poor meal intake.
Dietary protein restrictions are contraindicated in some situations because of significant
compliance issues, presence of decubitus ulcers, or malnutrition. Dietetics practitioners should
assess each situation individually and use clinical judgment to recommend appropriate medical
nutrition therapy for each patient with chronic kidney disease.
A primary concern with the elderly long-term care population is whether or not protein
restriction negatively affects quality of life and results in malnutrition from poor intake. Dietetics
practitioners should assess each situation individually, and use age, quality of life, and coexisting
medical conditions to determine appropriate medical nutrition therapy recommendations.
References and recommended readings
Academy of Nutrition and Dietetics. Nutrition Care Manual®. Available to subscribers at:
www.nutritioncaremanual.org. Accessed December 12, 2012.
Bailie GR, Johnson CA, Mason NA, St Peter WL, eds. Chronic Kidney Disease 2006: A Guide
to Select NKF-KDOQI Guidelines and Recommendations. Available at:
http://www.kidney.org/professionals/kls/pdf/Pharmacist_CPG.pdf. Accessed December 2, 2012.
MedlinePlus. Kidney failure. Available at:
http://www.nlm.nih.gov/medlineplus/kidneyfailure.html. Accessed December 2, 2012.
Review Date 12/12
R-0510