If you suffer from kidney failure -- also called renal failure -- your nephrologist will probably have you consult a renal dietitian. You may need to adjust your diet if your kidneys can no longer filter various substances from your blood. When it comes to a renal failure diet, one size does not fit all. The dietitian's advice is based upon your unique lab results for potassium, phosphorus, urine protein and other factors. Never restrict protein intake unless your nephrologist or your renal dietician advises you to.
If your potassium levels creep up past 5.0 mg/dl, you may be advised to limit your potassium intake. Potassium concentrations on either side of the cell membrane are responsible for transmission of nerve impulses, including those impulses that make the heart beat. High potassium levels can result in irregular heart beats and even heart attacks. There are no hard and fast rules for knowing which foods are high in potassium and which are low. The U.S. Department of Agriculture database is the best source of information on potassium content.
Low Potassium Foods
Generally, a food that has less than 200 mg of potassium per serving qualifies as a low-potassium food. This includes 1/2 cup servings of carrots, blackberries, cherries, rice, pasta, grapes, mushrooms or onions. While a large latte is a high-potassium food, 8 oz of coffee is a low-potassium food. Some high-potassium foods like potatoes and squashes can be converted to low-potassium food by cutting them into small pieces and soaking them in ten times their volume of hot water. For example, 2 cups of potatoes should be soaked in 20 cups of water. After soaking them for at least two hours, rinse the food thoroughly before cooking.
As you approach renal failure, the level of phosphorus in your blood may increase. When this happens, the excess phosphorus starts to pull calcium from the bones. Damage to the bones can be prevented by taking a drug called a phosphorus binder, and restricting your intake of dietary phosphorus. High phosphorus foods that should be eaten sparingly include dairy products, beer, cola drinks, chocolate, beans and lentils.
During the early stages of chronic kidney disease, you may have been advised to limit your protein intake to preserve your kidney function. Some nephrologists suggest replacing part of the meat, chicken, beans and soy products that you would normally consume with fruits, vegetables and carbohydrates. This advice often changes as you approach renal failure; patients are often advised to eat more protein so that they can heal from transplant or transition to dialysis more easily.