The kidney diet (renal diet) is a set of guidelines for people with kidney disease. The types of foods prescribed depend on the level of kidney failure the patient is experiencing, but generally the diet involves controlling the amount of sodium, potassium, phosphorus, protein, and fluid that a person ingests. People with kidney disease should be under the care of a physician and a dietitian.
Normally functioning kidneys help to maintain proper levels of sodium in the body. One of the most important functions of sodium involves maintaining fluid levels. The easiest way to avoid excess sodium intake is to eliminate putting extra salt on foods. It is also important to avoid particularly salty foods (popcorn, potato chips, salted pretzels, bacon, etc.). Because salt contributes so much to the flavor of foods, it may be helpful to find replacements for it (lemon juice or herb mixtures).
When patients are experiencing kidney failure, their kidneys are no longer removing water from the body with proper efficiency. The worse that the kidneys are functioning, the more important it is for patients to monitor their fluid intake. Water retention can cause swelling in the feet and ankles, as well as other parts of the body. The most recommended method for preventing water retention is to monitor salt intake.
The body uses potassium for a variety of important functions such as maintaining fluid and electrolyte balance, sending nerve impulse to muscles, and aiding in metabolic processes. When a person’s kidneys are functioning normally they filter out excess potassium, helping to maintain the proper amount in the body. Without properly functioning kidneys, patients need to control their potassium intake. Many fruits and vegetables (oranges, broccoli, tomatoes, potatoes, carrots) are high in potassium. Apples, blueberries, grapes, strawberries, lettuce, and onions are all relatively low in potassium.
The body must maintain a proper balance of phosphorus and calcium in order to build and preserve healthy bones. Normally, the kidneys help to maintain this balance by removing excess phosphorus from the bloodstream. Patients with kidney disease may need to maintain this balance by keeping a kidney diet. If too much phosphorus builds up in the body it can pull calcium out of the bones, making them weak and easily breakable. People following a kidney diet may be told to avoid foods that are high in phosphorus (beer, soda, cheese, milk, yogurt, oysters, beans, peas, nuts, whole grain products).
Patients experiencing kidney failure must be careful about the amount of protein they consume because when the body breaks down protein urea is produced, and the damaged kidneys are no longer removing urea effectively. If too much urea builds up in the body it can cause serious illness.
For people with kidney disease, it is important to maintain the proper balance of electrolytes, minerals, and fluid in the bloodstream. For patients undergoing dialysis treatments, this becomes even more important. The kidney diet is designed to help patients find the best balance for their body. Patients with any level of kidney failure should be under medical supervision. A physician and a dietitian will usually need to work closely to make sure that patients are maintaining proper nutrition. The diet for dialysis patients is especially strict and should be taken extremely seriously in order avoid further complications. A doctor may also prescribe other treatments in addition to a special diet.
Registered Dietitians in the Nutrition & Health Center also provide other medical nutritional care at different medical conditions like: