Renal Diet for People with Kidney Failure or Disease

The kidneys maintain normal fluid and electrolyte levels within the body.  If their ability to perform this function decreases, it is important to modify your diet to prevent water retention and an imbalance of certain nutrients.  Such nutrients include protein, sodium (salt), phosphorus, and potassium.  If you suffer from chronic kidney disease or kidney failure, your doctor will advise you to limit foods that contain too much of these nutrients.  A specific diet may be recommended to protect your remaining kidney function, and for your overall health.

In general, a renal diet is high in fruits, vegetables, and fiber, but low in processed foods, animal proteins, fats, and sodium.

Balancing Salts, Fluids and Electrolytes

Healthy kidneys remove nitrogen-type wastes and excess water from the bloodstream.  They also convert vitamin D to its usable form, and balance the electrolytes in our bodies.  When kidney function drops below 50 percent, wastes and electrolytes can accumulate in the blood at dangerous levels.  Too much nitrogen, for example, can cause mental confusion or painful deposits in your toes, known as gout.  Your doctor will, therefore, set dietary limits and restrictions based on your remaining kidney function.  If you are receiving hemodialysis, blood tests will be done prior to your treatments to measure sodium, potassium, and ammonia levels.  If your lab results are too high, your diet will be further modified to reduce the amount of troublesome foods before the next appointment.  If the results of your blood work are normal, you may continue your current diet.  Keeping everything in balance takes considerable effort.  The dietitian at the dialysis clinic can assist you with any necessary changes to your diet.

Learning how to read food labels, including nutritions facts and ingredient lists, can be helpful.

In addition to a special diet, medicines may be prescribed to help control these electrolyte levels.  The renal clinic nurse can help you better understand your medications.  He or she can also notify your doctor (nephrologist) of any problems you may be experiencing that require a change on your treatment plan.

Sample Serving Size Comparisons

• 1/4 cup = a golf ball
• 1/2 cup = a tennis ball
• 1 cup = one fist
• one small fruit = baseball
• one pancake = the size of a DVD
• one potato = the size of a computer mouse

5 Nutrients to Monitor

• Protein
• Sodium (Normal levels for serum sodium are 135-145 mEg/L)
• Phosphorus (Normal levels for serum phosphorus are 1.8-2.6 mEg/L)
• Potassium (Normal levels for serum potassium are 3.5-5 mEg/L)
• Water and other fluids

Protein

Protein is important for muscle mass, cellular functions, and the immune system.  It is metabolized into its usable forms, albumin and amino acids, plus the “end products” ammonia and urea.   The latter two wastes are transported to the kidneys for removal from the body.  In the presence of chronic kidney disease, these wastes cannot be excreted properly.  Accumulation of them causes nausea, vomiting, headaches, confusion, and unsteadiness with walking.  Also, too much dietary protein can further damage the kidneys.  To prevent these complications, protein intake should be limited.  A low-protein diet means less ammonia and other wastes circulating in the bloodstream for the kidneys to get rid of.  However, some people who receive hemodialysis experience a loss of muscle and body protein.  In this case, your amount of dietary protein may be increased.  0.6 grams of protein per kg of body weight is a common daily limit for hemodialysis patients.  Dietary protein sources should be foods that are high in essential amino acids to prevent muscle loss.  Examples include eggs, milk, poultry, and meat.  Consuming sufficient calories helps prevent the breakdown of body protein.

Vegetables, grains, soy, nuts,  meats, fish, poultry, and legumes (lentils, beans, and peas) all contain protein.  When hemodialysis is not required, the majority of protein in your diet should come from non-animal sources.  This not only protects the kidneys, but also your cardiovascular health.  When loss of renal function requires hemodialysis, the additional protein from eggs, meats, fish, and poultry (chicken) can prevent muscle-wasting.  Use the list below to plan your meals.

g = grams, 1000 mg = 1 gram

• 1 ounce cooked meat, fish, poultry = 7 g
• 1 large egg = 7 g
• 1/2 cup cooked dried beans, peas, lentils = 8 g
• 1/2 cup tofu = 7 g
• 2 tablespoons peanut butter = 7 g
• 1 cup milk, soy milk, or yogurt = 8 g
• 1/2 cup putting or custard = 4 g
• 1 slice or 1 inch cubed cheese = 7 g
• 1/2 cup cottage cheese or ricotta cheese = 7 g
• 2 tablespoons Parmesan cheese = 7 g

Sodium

When kidney function is reduced, too much dietary salt increases the loss of albumin.  Never add salt to your food;  get rid of the salt shaker!  Many foods already contain some amount of sodium.  More salt also makes us thirsty, and want to drink more.  As a result, we retain more fluid than the kidneys can remove from the body.  In addition, our blood pressure goes up which puts a strain on our kidneys and heart.  Avoiding foods that are high in salt or sodium, therefore, helps stabilize body fluid and blood pressure.  If your kidney function is suffient enough, you may eat 2000 mg (2 grams) of sodium per day.  In cases of end-stage renal disease, 1000mg to 1500mg per day may be the recommended limit.  Table salt consists of sodium and chloride.   One teaspoon of salt equals 2g of sodium;  this is your sodium allowance for the day.   A salt substitute may be sodium-free, however, it is usually made with potassium.  Since dietary potassium must also be limited with kidney disease, talk with your doctor before using a salt substitute.

High Sodium Foods to Avoid

• canned vegetables and soups
• packaged seasonings and meal starters
• processed meats
• seafood
• ham, bacon, sausage
• chips, pretzels, nuts, salty snack foods
• pickled meats and vegetables
• butter (unless unsalted), garlic salt, seasoned salt
• barbecue sauce, soy sauce, ketchup, mustard
• processed cheeses and cheese foods

Tips for lowering sodium in your diet

• leave the salt shaker in the cabinet—out of sight is out of mind
• season foods with herbs and spices; garlic, onion, sage, rosemary, thyme, lemon juice, fruit
• read medication labels for “hidden salt,” and talk with your doctor
• avoid medicines that contain sodium such as antacids and laxatives
• dining out: ask for meals made without salt or MSG (monosodium glutamate)
• choose foods with less than 200 mg of sodium per serving
• avoid foods with salt or sodium listed as one of the first 4 ingredients

Phosphorus

Many foods contain phosphorus, but the type from fruits and vegetables is less irritating to the kidneys.   Phosphorus is also added to some processed foods and sodas as a preservative.  Too much phosphorus in the bloodstream can cause calcium to come out of the bones, making them brittle and prone to fractures.  To maintain the health of your kidneys and bones, a phosphorus-binding medicine may be recommended to reduce the amount of this electrolyte in your body.  For example, Tums attaches to the phosphorus in foods as it is digested in your stomach.  Instead of being absorbed into the bloodstream, this bound phosphorus stays in the intestines, and is excreted in the stool.

Most people with kidney failure should limit dietary phosphorus to 800-900 mg a day.  It is best to limit or avoid eating the following foods:

• baking powder
• beer
• bran cereals
• breads raised with baking powder
• caramel
• cheese (except cottage cheese)
• chocolate
• soda/pop beverages
• dried beans
• dried peas
• eggs
• fish
• milk and milk products
• organ meats (brain and liver)
• nuts
• peanuts and peanut butter
• poultry
• whole grains, whole wheat bread

Potassium

When the kidneys are not fully functioning, they do not properly remove potassium from the bloodstream.  Potassium helps muscles, including those of the heart, to contract and relax.  Too much potassium in the bloodstream can cause your heart to beat irregularly or even stop.  When the level becomes too high, it is known as hyperkalemia, and emergency treatment is necessary.  Unless your doctor suggests otherwise, limit potassium to 2000 mg each day.  You should avoid salt-substitutes and medications that contain potassium.  The following list will help prevent hyperkalemia.  Choose fruits from the medium and low potassium groups.

Low potassium foods less than 150 mg per serving

Medium potassium foods 150 to 300 mg per serving

High Potassium Foods Greater Than 300 Mg per Serving

Dialyzing Vegetables

You can prepare some vegetables in a way that removes some of their inherent sodium and potassium, called dialyzing vegetables.  Follow these directions exactly, and be sure to inform your doctor that you are using these methods.

1. Use fresh potatoes, carrots, beets, rutabaga
2. Peel the skins off of the vegetables
3. Slice them into 1/8 inch thick pieces
4. Soak in warm water for 2 hours.  Use a ratio of 10 times the amount of water to vegetables.
5. Rinse under warm water.
6. Cook for 5 minutes in a ratio of 5 times the amount of water to vegetables.
7. Serve only one portion
8. You may freeze the leftovers

Monitoring Your Fluid Intake

Because your kidneys cannot concentrate urine or produce enough of it, fluid can accumulate throughout your body.  It can settle into some areas of the skin, visible as foot, leg, or hand swelling.   To prevent this from occurring, you will need to limit the amount of liquids you consume.  Your doctor will determine how much fluid you should drink each day, and may it be adjusted based on your dialysis treatments.  For instance, your limit may be 6 cups per day.  To help you measure, there are 8 ounces in one cup, and 2 tablespoons in an ounce.

Anything that is a liquid at room temperature is considered a fluid and counts towards your daily limit.  These include:

• juice
• gelatin (Jell-O)
• ice cream
• ice cubes (one full cup of ice = 1/2 cup of water)
• liquid medicine
• popsicles
• water
• pudding
• beverages (soft drinks)
• milk
• soups

Fluid Formulas

• 1500 mL = 50 ounces = 6 1/4 cups
• 1000 mL = 33 ounces = 4 cups
• 300 mL = 10 ounces = 1 1/4 cups
• 240 mL = 8 ounces = 1 cup
• 120 mL = 4 ounces = 1/2 cup
• 60 mL = 2 ounces = 1/4 cup
• 30 mL = 1 ounce = 1/8 cup = 2 Tbs

Recording Your Daily Fluid Intake

This table can help you manage your fluid intake throughout the day.  Don’t forget to reserve enough fluid for taking your medicines;  this fluid is counted in the “other” column.

Measuring Fluid

Another way to keep track of your daily fluid intake is to fill a jar/jug with water with the total daily fluid allowance prescribed by your doctor.

1. Measure each item you eat or drink that counts as liquid
2. For each item, remove the same amount of water from the jar/jug
3. When jar/jug of water is empty, you have completed your fluid allowance for the day.

What You Can Eat

By now, I’m sure you’re wondering, “What can I eat?”  This table lists foods that, with the guidance of your doctor or dietician, should be OK eat.  However, you may have other health issues that require limiting some of these foods.  For example, if you have diabetes or heart disease, the sugary or higher fat foods on this chart may not be recommended.  Bring this list to your appointments, and ask if there are any concerns.

Sample Menus

Below are some sample menus plans made from our list of foods for a renal diet.  Use day 3 to create a menu plan of your own.  Breads and baked goods should be made with white flour, no baking powder, and using a milk alternative such as soy or other plant-based milk.