Kidney Diet Tips

Why a kidney-friendly diet helps those with chronic kidney disease

Chronic kidney disease happens slowly over time. If kidney disease is detected early enough, steps can be taken to help slow the progression to either delay or prevent total kidney failure and the need for dialysis or a transplant. Eating a kidney-friendly diet is one way to help slow the progression of kidney failure. In addition to cleaning the blood, the kidneys perform other important functions. Loss of kidney function has a direct impact on some important balances in the body.

What kidneys normally do and how a kidney-friendly diet helps the body:

  • Regulate fluid balance When kidneys begin to fail excess fluid builds up in the body. In stage 4 kidney disease, the pre-dialysis diet recommends limiting fluid consumption to help control fluid weight gain. In order to control thirst, high-sodium foods are not recommended.
  •  Balance minerals in the blood Sodium, potassium and phosphorus are minerals that can build up in the body when kidneys no longer work properly. For people who have chronic kidney disease (CKD) but are not on dialysis, sodium and phosphorus restriction is beneficial. Potassium restriction may not be required until late in stage 4.
  • Produce hormones that regulate blood pressure and red blood cell production As kidney function declines, so does the production of hormones that regulate blood pressure and red blood cell production. The kidney diet is low in sodium to help control blood pressure (and control thirst). In addition to a low-sodium diet, blood pressure medicine may also be prescribed. To stimulate red blood cell production and help prevent anemia, iron supplements and anemia medications may be prescribed.Convert vitamin D into its active form Vitamin D helps keep calcium in balance and bones healthy. As kidney function declines, phosphorus levels rise. The ability to activate vitamin D decreases, causing a decline in calcium absorption from the diet. A kidney regulated hormone called parathyroid hormone (PTH) begins to rise. This causes calcium to come out of the bones and into the bloodstream. Calcium can mix with phosphorus causing hard deposits in soft tissues such as eyes, skin, heart, lungs and arteries. A diet low in phosphorus keeps phosphorus in control. Special-activated vitamin D therapy and careful calcium monitoring help to restore balance and protect bones.
  • Filter waste Some of this waste comes from excess dietary protein the body does not need, and from body cell turnover. Many studies have shown that for those with chronic kidney disease eating a low-protein diet may help take some of the filtering burden off the kidneys and perhaps prolong their function. To keep a balance, adequate but not excessive protein is required.

Following the chronic kidney disease diet and getting good nutrition can help keep the body in balance and hopefully prolong kidney function. Most people feel better and become healthier when following the pre-dialysis diet and the advice of their doctor and renal dietitian.

Sara Colman, RDN, CDCES

Sara Colman, RDN, CDCES

Sara is a renal dietitian with over 30 years experience working with people with diabetes and kidney disease. She is co-author of the popular kidney cookbook "Cooking for David: A Culinary Dialysis Cookbook". Sara is the Manager of Kidney Care Nutrition for DaVita. She analyzes recipes and creates content, resources and tools for the kidney community. In her spare time Sara loves to spend time with her young grandson, including fun times together in her kitchen.