Chronic kidney disease -- often referred to as CKD -- is a condition where your kidney function is impaired. This disease often is measured in terms of stages, which indicate to what level your kidney function has been affected. Because the kidneys are your body’s main filtration system, your physician will recommend an adjusted diet based on how many minerals and nutrients your kidneys can filter. If you have been diagnosed with stage 3 CKD, your physician will recommend a low-protein diet.
Five stages of kidney disease exist, and physicians use a measurement called the glomerular filtration rate to determine kidney function. Your physician will use a blood test that measures your creatinine levels to determine your glomerular filtration rate. Creatinine is a waste product created when protein is broken down in your body. Your kidneys should filter creatinine, but when their function is impaired, creatinine can build up in the blood. Stage 1 is the mildest form of CKD, which indicates your kidneys are functioning at a normal level with a GFR higher than 90 ml/minute. Stage 3 kidney disease indicates your kidneys are filtering at a rate of about 30 to 59 ml/minute. If your kidney disease has progressed to this stage, you may begin experiencing more symptoms, including fluid buildup, high blood pressure, anemia and kidney pain.
Because the body cannot filter creatinine as effectively, your physician will recommend reducing your protein intake to minimize the amount of creatinine in your blood. While your recommendations may vary based on age and gender, stage 3 CKD patients will typically eat about 0.8 g of protein per kilogram of body weight -- 1 kg equals about 2.2 lbs. Because your protein intake is more limited, your physician will recommend choosing the very best protein sources, meaning those that are low in fat and eaten with minimal waste produced in the body. Examples of protein sources that meet these criteria include fish and eggs. You also can add protein powders to oatmeal or cereal to increase your protein intake.
Stage 3 CKD can affect your bones, so your physician may recommend limiting your phosphorus intake because excess phosphorus can rob the bones of calcium. Foods that are high in phosphorus include dairy products, dried beans, nuts, peanut butter and beer. Your physician also may recommend taking a medication called a phosphate binder that helps to reduce the amount of phosphorus your body absorbs.
Sodium is another factor that must be monitored when you have stage 3 CKD because you may be beginning to experience some effects related to poor fluid regulation. Excess sodium in your diet can attract fluids in the body. To reduce your sodium intake, avoid processed foods like hot dogs and frozen foods, in which sodium is used as a preservative.
- National Kidney Foundation; Nutrition and Chronic Kidney Disease; 2006
- National Kidney and Urologic Diseases Information Clearinghouse; The Kidneys and How They Work; February 2009
- DaVita; Dietary Protein and Chronic Kidney Disease; 2011
- Edinburgh Royal Infirmary Renal Unit; Chronic Renal Failure and Its Progression; April 2010
- DaVita; Stage 3 of Chronic Kidney Disease; 2011