If you have kidney disease, you may need to change how you eat.
Making simple tweaks — like eating more fresh fruit and vegetables and less processed foods — can have an impact.
A renal diet can help slow kidney damage and improve your overall health.
What Is a Renal Diet?
The kidneys filter waste from the blood and help keep the right balance of certain nutrients in the body. Kidney disease can prevent them from doing as good of a job keeping this balance.
That's why doctors often suggest a renal diet.
A renal diet won't cure kidney disease, but it can:
- Help reduce the risk of losing kidney function.
- Slow down disease progression.
- Keep you from having other health complications.
A renal diet is often low in sodium, phosphorus and sometimes potassium and protein.
Sodium and potassium are minerals that:
- Help maintain fluid balance in the bloodstream and cells.
- Keep our nerves and muscles functioning.
Phosphorus is a mineral that helps form bones and teeth and plays other important roles in the body.
Amino acids are the building blocks that make protein. They're essential for building body structures like muscle and maintaining many key body functions.
Your body needs all of these nutrients. But if you have kidney damage, you may not be able to maintain the correct balance or amounts.
Sodium, phosphorus, potassium, and protein byproducts can build up in the blood. This can cause your body to retain too much fluid and lead to imbalances in body function, and kidney damage getting worse.
What Are the Benefits and Risks of Renal Diets?
Sticking to a renal diet can help you manage your kidney disease and related complications.
Renal diet benefits
A renal diet can help slow kidney damage so you can have a healthier life and feel better.
Renal diet risks
A renal diet doesn't have any risks. Because it's also heart-healthy, it can improve both your kidney and complete health.
Some people may feel overwhelmed by the renal diet and end up being overly restrictive with their food intake. If you feel this way, work with your doctor or dietitian to discuss food and drink choices that work for you.
Who Should Follow a Renal Diet?
Anyone with kidney disease should think about a renal diet.
Your doctor may want you to meet with a registered dietician to discuss renal diet considerations and learn recipes.
If you have advanced kidney disease or other health conditions, your doctor or dietitian may have different guidelines for your renal diet.
For instance, people with early kidney disease versus those on dialysis may need to restrict their protein intake. They may also need more potassium.
Top Healthy Foods for People with Kidney Disease
You can enjoy many healthy foods when you follow a renal diet:
- Veggies — cabbage, red bell peppers, cauliflower, and onions.
- Fruits — apples, cranberries, blueberries, raspberries, strawberries, cherries, and red grapes.
- Proteins — lean meat, skinless poultry, eggs, and fish.
- Seasonings and oils — fresh or dried herbs, spices, garlic, and olive oil.
- Whole grains — barley, buckwheat, bulgur, wild rice, and unsalted popcorn.
Renal diet tips
There are tips to keep in mind if you or a loved one is on a renal diet.
If you have kidney disease, you should:
- Choose fresh foods and cook from scratch as much as you can.
- Avoid fast food and packaged foods. They're high in sodium.
- Use spices and fresh or dried herbs instead of salt to flavor food.
- Rinse canned beans and vegetables before cooking to help remove excess salt.
- Keep protein serving sizes small. A serving size of protein is 2 to 3 ounces of chicken, fish, or meat.
- Limit alcohol to one drink a day for women and two for men.
How much water should I drink on a renal diet?
You will likely need to track how much water you drink in the later stages of kidney disease.
Drinking too much water may cause fluid to build up in your body because you have decreased urine output. Increased fluid in the body puts excess pressure on your heart and lungs.
Your doctor will tell you how much fluid you should take in each day.
Besides water and other drinks, you need to factor in the fluids used in cooking. Foods that melt at room temperature (such as popsicles or gelatin) also count toward your fluid intake.
If I follow a renal diet, what should I know about sodium?
With kidney disease, your kidneys can't remove excess sodium from the body.
This causes fluid build-up in the tissues and bloodstream, and symptoms such as:
- Increased thirst.
- High blood pressure.
- Shortness of breath.
- Heart failure.
You should try to limit sodium you consume with meals and snacks.
To help cut back:
- Read food labels.
- Watch your serving sizes.
- Choose fresh over packaged foods.
- Cook from scratch to control how much salt goes into your food.
What should I know about phosphorus with a renal diet?
Phosphorus is crucial to form and maintain bones. But if your kidneys aren't working right, they don't remove excess phosphorus from the blood.
Many foods have added phosphorus, or phosphate additives, that the body absorbs well. This can cause problems for a lot of people.
Always read the ingredients list on food labels and look for words with the letters “PHOS."
Foods that often contain phosphate additives include:
- Colas and other bottled beverages.
- Processed meat products.
- Baked goods.
- Canned fish.
- Fast food.
Other foods that are naturally high in phosphorus include:
- Dried beans.
- Ice cream.
Your doctor or dietitian can help you manage your phosphorus levels based on your needs.
If I follow a renal diet, what should I know about potassium?
Potassium is an important mineral that helps to maintain fluid and electrolyte balance. It also helps our heart, nerves, and muscles function.
Getting enough potassium is vital in the early stages of kidney disease.
As kidney disease progresses, the kidneys may have a hard time removing excess potassium in the body. This can result in potassium ranges in the blood rising above the recommended range, a condition known as hyperkalemia. If you are at risk for hyperkalemia, your doctor may recommend that you limit your potassium intake.
Foods that are high in potassium include:
- Salt substitutes made with potassium.
- Dried fruits.
- Tomato sauce and juice.
You can also remove some of the potassium in certain fruits and vegetables. Just peel and soak them in water before cooking.
If I follow a renal diet, what should I know about protein?
We all need protein in our diet. But if you have kidney disease, it's easy to overdo it.
Damaged kidneys have to work harder to remove protein waste from the blood. This causes more stress on organs that don't function well, to begin with.
If you're not on dialysis, your doctor will limit the amount of protein you eat.
If you've started dialysis, you will likely need to eat more protein. Dialysis does the work of your kidneys and removes protein waste from the blood. You may need extra protein to keep your body functioning properly and prevent muscle loss.
The type of protein you eat is vital. Protein comes from both plants and animals, and most people eat both types.
Good protein sources for someone with kidney disease include:
- Beans and lentils (in small amounts, as they also contain phosphorus).
- Fish or seafood.
- Lean beef (like sirloin or tenderloin).
- Skinless poultry.
Your doctor or dietitian is the best resource to figure out the best renal diet for you.
Portion sizes and foods to avoid will vary from person to person. Your exact renal diet will also depend on your size, age, and the stage of your disease.
Contact the UPMC Kidney Disease Center
To learn more about treatment for kidney disease at UPMC:
- Book an appointment or video visit with a UPMC kidney expert.
- Call the UPMC Kidney Disease Center at 1-412-802-3043.
- Email the UPMC Kidney Disease Center.