Your doctor or dietitian may recommended that you make dietary modifications when your kidneys are not working well enough to get rid of excess water, clear waste, and balance certain minerals in your body. The main areas you may have to modify include fluid, protein, potassium, sodium, and phosphorus intake. Your doctor or dietitian may also suggest that you take certain supplements.
When the kidneys are not working properly, urea builds up in the body and contributes to symptoms such as fatigue, nausea, headaches, and a bad taste in the mouth. Since protein breakdown produces urea, you may need to reduce your protein intake. Although protein intake used to be significantly restricted, studies have shown that there wasn't much benefit of severe restriction. Most experts recommend a diet that contains 0.8 grams to 1.0 gram of protein per kilogram of body weight per day. If your protein intake is reduced, you will need to get the energy you need from other food such as carbohydrates and fats.
Sodium affects how much fluid your body holds on to and also affects your blood pressure. If you eat too much sodium, you will retain more water and your blood pressure may increase. Try to stay away from foods that are high in sodium such as processed foods, canned soups, and luncheon meats. Use herbs to give your food more taste or look for low-sodium options. It is especially important to watch your sodium intake if you have high blood pressure, heart failure, or swelling of your feet, ankles, or legs.
When your kidneys are not working properly, the levels of potassium in your body can increase. If the levels get too high, they can affect your heartbeat. You may need to restrict your potassium intake and go easy on foods that are high in potassium (e.g., bananas, potatoes, tomatoes). Your doctor or dietitian will tell you how much potassium you can consume and will show you how to track your potassium intake.
Phosphorus is a mineral that is important for bone health, but too much phosphorus can cause bone pain and itchy skin. You may need to reduce your intake of phosphorus-containing foods, such as milk, cheese, and protein. You may need to avoid foods that have high levels of phosphorus, such as seeds, beans, certain bran cereals, and nuts. To help control your phosphorus levels, your doctor may prescribe medications that bind phosphorus in your intestines so it isn't absorbed.
In addition to watching your intake of protein, sodium, potassium, and phosphorus, you may need to restrict your fluid intake if you have high blood pressure or swelling of the hands, feet, or face. Also, because you may have to limit certain foods in your diet, you may need to take vitamin and mineral supplements such as a multivitamin or iron, vitamin D, or calcium supplements.
Your health care team will recommend a diet and supplements that are best suited to you, as not everyone with kidney disease needs the same thing.
Written and reviewed by the MediResource Clinical Team