People with chronic kidney disease (CKD) might be told to follow a renal diet. CKD is a condition that occurs when the kidneys do not function properly and cannot filter waste from the blood as they normally would. A renal diet is a specific type of diet that can help manage symptoms and prevent the worsening of CKD.

 

What is the renal diet?

A renal diet prioritizes fruits, vegetables, grains, protein, and heart-healthy fats while limiting foods that put stress on the kidneys. This diet is often low in sodium, potassium, and phosphorus. Lower protein intake may also be recommended for those who don’t receive dialysis. 

 

What should I know about sodium and salt?

The human body requires a small amount of sodium, about 500 mg of sodium daily, to allow nerve signaling, contraction and relaxation of the muscles, and to maintain the proper balance of water and minerals.

 

When too much sodium is consumed, it can cause fluid retention. Fluid retention can increase blood pressure and put more strain on the kidneys. Being mindful of salt intake can help manage these symptoms. 

 

Salt is one of the most commonly used seasonings and is often found in packaged, frozen, and canned foods. If you want to lower your sodium intake, consider the following:

 

• Experiment with spices and seasonings to add flavor instead of using salt.
• Read the nutrition labels on packaged foods. Look for foods that have less than 300mg sodium per serving. 
• Choose foods that don’t list salt as one of the first 5 ingredients. 
• Try reduced-sodium soups. Check the food label for potassium chloride as an ingredient. Some people may need to monitor the amount of potassium they eat when following a renal diet. 
• Look for canned vegetables that say “no salt added” on the label. Rinse canned vegetables twice before eating to lower the amount of salt.
• Look for lower salt or no-salt-added options for your favorite foods like peanut butter or box mixes.

 

The amount of sodium for a renal diet is 2000 mg or less per day. Check with your doctor or dietitian to find out which sodium goal is right for you. 

 

What should I know about phosphorus? 

Phosphorus is a mineral found in each cell in your body. Most phosphorus is kept in the bones and teeth, and some is in your DNA. Your body needs phosphorus to make energy and to carry out many important chemical processes.

 

When you have CKD, your kidneys cannot remove excess phosphorus from the blood very well. High phosphorus levels can cause the body to pull calcium out of your bones, making them more weak and brittle.

 

Dairy foods are high in phosphorus, so consider drinking only 1 cup (8 oz) of milk per day. If you enjoy eating yogurt or cheese, enjoy them in smaller portions (1 container of yogurt, or 1.5 oz of cheese). 

 

You might want to consider eating the following high-phosphorus foods less often or in smaller portions:

 

• Milk, yogurt, cheese, or ice cream
• Dried beans like kidney, black, or pinto beans
• Mushrooms
• Cocoa
• Beer
• Dark soft drinks like colas or root beers

What should I know about potassium? 

Potassium is a mineral involved in making your muscles work. When you have CKD, potassium may build up in your blood. This can cause changes in your heart rate and increase the risk of a heart attack.

 

Fruit and vegetable choices

Many fruits and vegetables are high in potassium, and you might have to limit them or eat small portions. A renal dietitian can help you decide which fruits and vegetables you might want to avoid and how much is the right amount for you. 

Some fruit and vegetable options that are lower in potassium include:

 

• Apples
• Blackberries
• Blueberries
• Cherries
• Grapes
• Pineapple
• Strawberries
• Tangerines
• Green beans
• Cabbage
• Cucumbers
• Eggplant
• Kale
• Lettuce
• Sweet peppers
• Zucchini

 

Grain and starch choices

Whole grains are nutrient-dense, providing fiber, vitamins, and minerals, but many are high in potassium. You may want to choose smaller portions and be mindful of how often you eat whole grains. 

 

Some good grain options low in potassium include:

• Barley
• Buckwheat
• Bulgur
• Wild rice
• Unsalted popcorn

 

White bread, pasta, or rice are lower in potassium than their whole-grain counterparts. Ask your dietitian if these are better options for you.

 

What should I know about protein?

Your body needs protein to help build muscle, repair tissues, and fight infection. If you have kidney disease, you may need to eat smaller portions of protein. Eating too much protein might cause waste to build up in your blood, and your kidneys may not be able to remove the extra waste. If protein intake is too low, however, it may cause other problems so it is essential to eat the right amount each day.

 

Some good protein options include:

 

• Skinless chicken or turkey
• Fish or seafood
• Lean beef like sirloin or tenderloin
• Eggs
• Tofu and beans, like kidney beans or lentils (note that these are higher in potassium and phosphorus, so you may need to limit the portion size)

 

The amount of protein you need is based on:

• your body size
• stage of kidney disease
• the amount of protein in your urine

 

Your dietitian or healthcare provider can tell you how much protein is right for you.

 

Other ways to manage CKD

In addition to following a renal diet, you can manage CKD by staying hydrated, monitoring blood pressure, and participating in regular movement and activity.

 

Staying hydrated is important for kidney function, as it can help flush out waste and toxins from the body. Check with your healthcare provider about whether you need to limit your fluid intake.

 

Stroke survivors who have CKD may be instructed to follow a renal diet to manage their condition. The renal diet is low in sodium, phosphorus, and potassium. Sometimes lower protein intake may also be recommended. Consider working with a healthcare provider or registered dietitian to create a personalized renal diet plan.

 

 

 

References

 

Zhang, J., Li, Y., Li, L., Li, Y., & Wang, Y. (2021). The effects of a renal diet on patients with chronic kidney disease: A systematic review and meta-analysis. Journal of Renal Nutrition, 31(3), 246-255. doi: 10.1053/j.jrn.2020.07.008

 

Nutrition and early kidney disease (stages 1–4). National Kidney Foundation. (2022, August 29). Retrieved April 30, 2023, from https://www.kidney.org/atoz/content/nutrikidfail_stage1-4

 

Fiaccadori, E., Sabatino, A., Barazzoni, R., Carrero, J. J., Cupisti, A., De Waele, E., Jonckheer, J., Singer, P., & Cuerda, C. (2021). Espen guideline on Clinical Nutrition in hospitalized patients with acute or chronic kidney disease. Clinical Nutrition, 40(4), 1644–1668. https://doi.org/10.1016/j.clnu.2021.01.028