What to Eat When You Have Kidney Disease

Should I be on a low-phosphorus diet if I have kidney disease?

Ask your doctor or renal dietitian—the answer will often be yes. Phosphorus is a mineral found mostly in dairy products and meats. Your body uses it to form strong bones and teeth. But starting in the earlier stages of chronic kidney disease (CKD), your kidneys begin to lose the ability to remove extra phosphorus from your body. Because too much phosphorus can harm your bones, it makes sense to eat less phosphorus.

Some experts think 800 to 1,200 mg. of phosphorus per day is a good target. Food labels are not required to list phosphorus, so you will need to talk to a renal dietitian or find a nutrition reference guide and look up foods. You'll soon learn the phosphorus values of the foods you eat most often.

If you are also on a lower protein diet, a low-phosphorus diet is easier because foods high in protein tend to be high in phosphorus, too. Your doctor may want you to limit dairy servings each day and take a calcium supplement. Taken with meals, calcium supplements act as phosphate binders, because they lock on to extra phosphorus and keep your body from absorbing it.

Should I be on a low-potassium diet if I have kidney disease?

Having the right level of potassium in your body helps all your muscles work smoothly—including your heart. So, to stay as healthy as you can, you need to keep just the right level of potassium in your blood (not too much, not too little). Keeping potassium at the right level all the time is one of the jobs that healthy kidneys do for your body. When kidneys fail, they start to lose this ability.

Your potassium level should be checked regularly with a blood test. If your levels are too high, your doctor will ask you to start a low potassium diet.

Many foods have potassium, but some such as avocados, dried fruits (including raisins, apricots and prunes), potatoes, oranges, bananas and salt substitutes are very high in potassium. If you need to limit potassium, your dietitian will help you learn which foods have more and which foods have less potassium.

Should I be on a low-protein diet?

Protein—found in meats, fish, poultry, dairy products, nuts and some grains—helps your body form muscle and tissue. But when your kidneys are not working well, the byproducts of protein breakdown can build up in your blood. This can make your kidneys work harder.

Many people with kidney disease find that they don't want to eat as much protein as they used to, because food doesn't taste the same. You may even need to make a special effort to eat enough protein and calories, because having kidney disease can reduce your appetite.

In all cases of CKD, it's crucial to avoid malnutrition. A blood test for albumin, a form of protein, is a good way to tell if you are getting enough quality food. Your albumin level should be 4.0 g/dL or higher. If you notice weight loss, loss of appetite or other signs of poor nutrition, talk to your doctor or a renal dietitian.

If your diet includes very little protein, your doctor may prescribe supplements of nutrients you would normally get from protein, including ketoacids and/or amino acids.

To figure out how much protein is in the food you're eating, read labels and use nutrition reference tables. A renal dietitian has special expertise helping people with kidney disease put together healthy meal plans. Check with your doctor or dietitian before making any changes to the protein level in your diet.

Loss of appetite and kidney disease

Poor appetite is a common symptom of advanced kidney disease. Even if you are not hungry, it is important to eat and keep good nutrition. Get good nutrition in various ways:

Eat more bland or starchy foods.
Avoid cooking smells if they bother you—cook ahead and freeze meals that you can microwave, or look for low-salt convenience foods.
Try a liquid nutritional drink like Boost or Ensure once a day. (Do not rely on these drinks entirely, as their protein, phosphorus and potassium content is high—consult a dietitian beforehand.)
Have several small meals instead of one large one.
Watch cooking shows on television to tempt your appetite.
Boost the protein content of your meals by adding egg whites, egg white powder or protein powder. Also eat small portions of protein foods at a cold temperature, such as egg salad or a cold chicken sandwich.
Get help from a renal dietitian if lack of appetite continues. If you are in stage 5 CKD and your appetite or nutritional well-being does not improve, this may be a sign that you should start dialysis. Many people find their appetite improves after some time on dialysis.