The kidneys remove waste and excess fluids from the body, which are excreted through urination. When a person has kidney failure, also known as renal failure, damaged kidneys are not able to filter the wastes and fluid and dangerous levels of both develop. Patients with end-stage renal disease require dialysis several times a week to manually removes excess waste and fluid from the body.
Purpose
A renal diet helps the body maintain a balance of electrolytes, minerals and fluid between hemodialysis treatments. Dialysis does not remove all waste products in the body and following a renal diet is important because waste products can build up in between treatments. Fluid restriction is also necessary because most dialysis patients urinate very little or not at all.
Calorie Needs
An adequate amount of calories is necessary for energy, weight maintenance and building muscle and tissue. Because renal diets usually limit the amount of protein a patient can eat, calories must be eaten from other foods. A dietician can help a patient understand what foods can be eaten in small amounts, but that are calorie dense. Fats, such as oils and margarine, provide a good source of calories, but are low in saturated fats and cholesterol. Jelly, sugar, jam, honey and syrup may also be recommended, especially to patients who have a decreased appetite, because they are high in calories and easy to add to the diet.
Potassium and Phosphorus
Phosphorus is necessary to maintain healthy bones, teeth and normal function of the nerves and muscles. It works with calcium, and patients with kidney failure have a difficult time balancing phosphorus and calcium. In these patients, the body cannot get rid itself of excess phosphorus, and calcium levels decrease. Symptoms of excess phosphorus in the body include itchy skin, joint pain and brittle bones. Foods high in phosphorus include cola, peanut butter, cheese, sardines, chicken, nuts, beer and ice cream. Low-phosphorus foods include broccoli, non-dairy milk substitute, sherbet, hard candies and zucchini. It is important to remember that eating many low-phosphorus foods can be equivalent to eating a high-phosphorus food.
Excess potassium in the body can be dangerous. Potassium helps keep the nerves and muscles, including the heart, functioning properly. The kidneys help keep appropriate amounts of potassium in the body, and high levels can cause the heart to beat irregularly or to stop beating. Almost all food contains some potassium. Some high potassium foods include bananas, broccoli, chocolate, oranges, potatoes, coffee, tomatoes, raisins and nuts. Low-potassium foods include apples, rice, grapes, cucumbers, watermelon, cereal, lettuce and cherries.
Fluids
Between dialysis treatments, fluid builds up in the body, which can cause excess water retention in the heart, lungs and ankles. Symptoms of excess fluid include swelling, shortness of breath and high blood pressure. A doctor is able to tell a dialysis patient how much fluid they should be drinking each day. Anything that can be melted from a solid to liquid, including popsicles, ice cream and sherbet is considered a fluid. The Medical College of Wisconsin Department of Nephrology states that drinking only when thirsty, chewing gum and sucking on lemons can help with a patient's thirst. The total amount of fluid a patient is allowed can be measured out at the beginning of the day and placed in a container to help monitor the patient, and make sure they are not going over the allowed amount. A doctor may ask a patient to cut down on the amount of sodium in the diet because these foods can also cause fluid retention.
Protein Recommendations
Protein is necessary to build muscle, repair tissue and fight infections. Doctors may prescribe a low-protein diet or a moderate-protein diet before dialysis, the National Institutes of Heath states. A moderate-protein diet includes one gram of protein per kilogram of body weight each day. When a patient starts dialysis, patients may require a high protein diet and doctors may ask the patient to eat 8 to 10 oz. of protein rich foods each day.
