The kidneys filter waste from the blood and maintain the right balance of fluid in the body. They also play an important role in regulating blood pressure. In general, people with impaired kidney function are advised to eat a diet that supports healthy blood pressure and good blood sugar control. This means avoiding foods high in salt, sugar and trans fats. It may also be important to avoid excessive protein consumption and foods high in potassium and phosphorus. Specific dietary restrictions should be discussed with your doctor since individual requirements vary.
Processed and Fast Food
Processed and fast foods are often high in salt, sugar and unhealthy fats. Avoiding these is a good idea for anyone with kidney problems. This includes snack foods like chips, crackers and cookies as well as prepackaged frozen meals, canned soups and other convenience foods. Even foods that may seem healthy -- like canned vegetables and fruits -- may be high in salt or sugar. Low-sodium canned or frozen vegetables and fruits packed without added sugar are a good option when fresh produce is not available.
Too Much Protein
You may need to limit the amount of protein you eat since excessive protein intake can make kidney problems worse. The National Kidney Disease Education Program advised in June 2014 that people with chronic kidney disease limit daily protein consumption to roughly 0.36 to 0.45 g per pound of body weight. This moderate approach to protein consumption provides approximately 54 to 67.5 g of protein daily for a 150-pound person and allows for a modest serving of protein with each meal.
Foods High in Potassium and Phosphorus
Depending on the type and severity of kidney problems you are experiencing, you may be advised to limit foods high in potassium and phosphorus since these minerals can build up in the blood when the kidneys are not functioning properly. Your health care provider may advise you to avoid salt substitutes that might be high in potassium and limit foods that are potassium-rich. These include milk, yogurt, avocados, bananas and many other fruits and vegetables, nuts, seeds and beans. Foods high in phosphorus include most soft drinks, dairy products, nuts, liver and beans.
A Word of Caution
When your kidneys are not functioning normally, your blood might become too acidic or your potassium levels might rise to abnormal levels -- which can be influenced by your diet. Symptoms of these chemical imbalances include nausea, vomiting, fatigue, numbness, tingling, skipped heartbeats, dizziness when standing and weakness. Contact your doctor right away if you experience any of these symptoms.
- National Institues of Health: National Kidney Disease Education Program: Chronic Kidney Disease (CKD) and Diet -- Assessment, Management, and Treatment
- Kidney International: KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease
- Merck Manual: Chronic Kidney Disease
- National Kidney Foundation: Potassium and Your CKD Diet
- National Kidney Foundation: Phosphorus and Your CKD Diet