Diet & Your Kidneys

Diseased kidneys can no longer remove enough wastes and fluid to keep you healthy. Many of these wastes come from the foods and beverages we eat and drink. Dialysis removes the majority of the waste, but not all.

That’s why it’s important for dialysis patients to control what types of food they eat and how much. By closely following your diet and eating the right foods, you can maintain optimal health and avoid complications.

Diet recommendations are highly individualized and based upon your level of kidney function, body size, age, gender, blood test results and any other medical problems you may have. Although every renal diet has some basic similarities, do not follow the dietary recommendations of another patient.

At Washington University/Barnes-Jewish Hospital, you will be assigned to a dietitian who will work directly with you and your family to plan meals and guide you on the right food choices. Your dietitian will meet with you at least once a month to go over results from laboratory blood tests and adjust your diet accordingly.

There are several guidelines to follow while learning your new diet:

  • Follow your recommended plan when choosing what to eat at all of your meals.
  • Use only the foods listed on your diet plan and in the amounts shown. Do not add new foods until you talk with your dietitian.
  • Read and use information from food labels carefully.
  • Prepare and serve food without adding salt or salt substitutes.
  • Measure your food and fluids accurately.

Important nutrients

In planning your diet, dietitians will take into account your food preferences and cultural background. Your dietitian will help you get the right amount of calories and the right amount of the following:

  • Protein: Protein is critical to build and repair tissues such as muscles, bones and skin, and to resist infections. Protein, however, leaves behind a waste product call urea that is removed by the kidneys. Before you started dialysis, you may have been on a low-protein diet to limit the amount of waste products in your blood. Now that you have begun dialysis, your diet can include more protein because dialysis helps to remove these wastes, including urea. Your dietitian will carefully regulate your diet to ensure the right amount of protein is in your meals.
  • Sodium: Sodium, or salt, is used in the body to control blood pressure, balance fluids and control muscle contractions. But if there is too much sodium, you can become thirsty and your body will retain more fluid, which can cause swelling, high blood pressure or shortness of breath. It’s vital to limit your sodium intake to avoid these potential problems. You will learn how to buy and prepare lower sodium foods.
  • Potassium: Potassium is a mineral that helps to keep nerves and muscles working properly. Both high and low levels of potassium can cause serious health problems. The kidneys help balance potassium levels in the body. In patients with kidney failure, potassium levels are controlled through dietary choices and receiving dialysis treatments. Most patients undergoing in-center dialysis need to limit their intake of high potassium foods because potassium builds up in the body between dialysis treatments. A few foods high in potassium include bananas, tomatoes, oranges and potatoes.
  • Phosphorus: Phosphorus, along with calcium, works to keep your bones healthy and strong. When kidneys fail, phosphorus builds up in the blood, causing a drop in calcium levels. This can cause weak bones, damaged blood vessels and heart disease. Your phosphorus level will be controlled by food choices, dialysis and medications. Phosphorus is found in almost all foods but is especially high in dairy products, cheese, dried beans, liver, nuts and chocolate.
  • Fluids: When kidneys don’t function, your body can’t eliminate excess fluids. Excess fluids can cause swelling, shortness of breath and high blood pressure. Keep in mind that fluids include any food or beverage that is liquid at room temperature, so ice and frozen desserts and gelatin must be counted as fluids. Your fluid limit is recommended by your doctor and is based upon your urinary output and an amount of fluid that can easily be removed during dialysis.


Kidney disease and dialysis change the amounts of vitamins your body needs. Your special diet also may limit some food groups that normally would provide important vitamins. Your doctor may prescribe important vitamins for you. Be sure to take only those supplements that are ordered by your doctor. Some vitamins may be harmful to your health if you are on dialysis.

Diabetes and your diet

If you already are on a special diet because of diabetes, your dietitian will help you combine the diabetic with the dialysis diet. By working with your dietitian, you may need to make only a few changes that will keep your diet in line while on dialysis.

Dining out

You don’t have to stop visiting family members, friends, or your favorite restaurant while on dialysis. You will, however, need to learn how to make smart meal choices that are in line with your recommended dietary guidelines. The easiest way to understand and select appropriate foods is to talk about the choices you might make in your favorite restaurants with your dietitian who can help you make the best decisions. That way, selections and portion control can be reviewed and discussed. Many restaurants also have healthy foods and smaller portions that are in line with your individual diet recommendations.

Emergency meal planning

In the event of an emergency or power outage, you need to be prepared to follow a limited diet if a dialysis treatment has to be missed. Your dietitian can provide you with a three-day emergency meal plan that includes both a grocery list and recommended servings for each meal. Remember to regularly check for expiration dates and to rotate your emergency food stock.

It is all about you

It is important to follow through and learn about your individual dietary needs. Because every person is different, a diet should not be started without the recommendation and supervision of your doctor and dietitian. Each diet plan is specific to each person. What may be helpful to one patient may actually harm another, so make sure to follow your own diet recommendations.