So, you’ve been recently diagnosed with Chronic Kidney Disease (CKD). Your doctor walked into the room to discuss results from your blood work, and she started discussing the glomerular filtration rate of your kidneys, your BUN and creatinine levels, and the only words you could understand were “kidney” and “disease.” Your first thought may have been, “I feel fine. I don’t have any symptoms of kidney pain.” Your second thought, “What does all this mean?”
Denial and confusion about chronic kidney disease are often the first reactions when diagnosed. However, being in denial has an upside– it hopefully means you feel well and can’t believe that you have chronic kidney disease. While there are five stages of chronic kidney disease, oftentimes, patients don’t have visible symptoms and are diagnosed when already at CKD Stage 3.
If you haven’t already, this is the time to do everything you can to slow the progression of Chronic Kidney Disease and lessen its adverse effects. How do you do that? You begin by educating yourself. Learn about BUN and creatinine. Learn about the glomerular filtration rate. Talk to your kidney specialist. Ask questions and learn how your diet can help you continue to feel well and slow the progression of kidney disease.
If you have other conditions, it’s time to learn about those too. Learn about how those conditions affect kidney disease. Talk to your dietitian about diabetes, high blood pressure, heart disease, cardiovascular disease, fluid retention, bone disease, muscle cramps, and obesity. Addressing these conditions should occur in conjunction with managing your chronic kidney disease. You may be at higher risk of permanent damage and overall health decline with multiple conditions.
A holistic understanding of your health will be critical to building a treatment plan and addressing any lifestyle changes you may need to undertake. The most critical objective at this stage is to keep your kidneys working properly and reduce further loss of kidney function.
Step 1: Understanding your doctor
Blood Urea Nitrogen (BUN)
Your doctor will conduct several blood tests to determine the level of your chronic kidney disease CKD. When you have Stage 3 kidney disease, your doctor looks at white and red blood cells, your BUN and creatinine, and other enzymes that indicate overall kidney function. Your blood urea nitrogen (BUN) level is critical. When your body metabolizes protein, it produces urea. The kidneys filter the urea from the blood into the urine.
Your doctor will run a test that measures the amount of nitrogen from urea–a BUN test. Healthy kidneys work by removing urea from the blood and preventing BUN from rising excessively. A high level of BUN is one of the symptoms indicating that the kidneys are not functioning well. Your kidney doctor, called a nephrologist, may recommend consuming less protein. He or she will also monitor other health conditions you may have and certain medications you may take.
Creatinine is a waste product that is filtered out of the blood by the kidneys and passed into the urine. If the amount of creatinine in the urine decreases, while the amount in the blood increases, this may signify that your kidneys are damaged and aren’t functioning well.
BUN to creatinine ratio – Your nephrologist or doctor will use this to determine if your kidneys are functioning correctly.
Estimated Glomerular Filtration Rate eGFR
Your eGFR tells your doctor how much kidney function you have based on how well your kidneys filter waste and extra fluid out of your blood. A eGFR test is usually conducted early in the diagnosis process. As chronic kidney disease progresses, your eGFR number decreases. You have approximately a million glomeruli of tiny filters inside the kidneys that filter out waste. Your eGFR indicates your chronic kidney disease stage. Starting with healthy kidney function, early stages of kidney disease, mid-stage with moderate kidney damage, later and end-stage kidney failure. The following chart defines specific stages and eGFR stages.
Estimated Glomerular Filtration Rate (eGFR)
Kidney damage (some protein in the urine) with normal GFR
Greater than 90
Kidney damage with mild decrease in GFR
60 to 89
Moderate decrease in kidney function
30 to 59
Severe kidney damage
15 to 29
Kidneys are close to failing or have already failed
Less than 15
Step 2: Find a Registered Dietitian (RD)
Registered Renal Dietitians specialize in nutrition that reduces kidney disease progression. Proper nutrition for someone with kidney disease is very different from someone with healthy kidneys. The RD does not provide medical advice. Instead, he or she will have one goal: preserve kidney function. Together, you will discuss the pros and cons of nutrients depending on your medical conditions. Your dietitian will help you:
- Understand what you can eat to slow the progression of kidney disease.
- Learn what you can substitute for no-longer-allowed foods.
- Learn to read food labels.
- Help you define a diet that will support your weight loss goals, if needed.
Make sure your RD has the proper credentials. Your doctor may have a recommendation for you. You can also find guidance at the National Institute of Diabetes and Digestive and Kidney Diseases. Note that all nutritionists are not dietitians. But, all dietitians are nutritionists.
Step 3: Understanding your RD
Your dietitian will explain the stage of your kidney disease and what it means for your diet. In the later stages of kidney disease, the recommendation for nutrients and liquids may change to help lessen the progression of the disease. In Stages 1 and 2, nutrients to consume may be less restricted. Stage 3 may call for some restrictions. Stages 4 and 5 will definitely present limitations to your diet. If on dialysis, further restrictions, including limiting fluid intake, will likely be advised.
Your dietitian will talk about phosphorus, potassium, protein, sodium, and fluids in your diet. While learning what you should eat is essential, you must also understand what you shouldn’t. So, let’s start with sodium.
Patients with high blood pressure, diabetes, or kidney disease are often told to avoid sodium. Of course, that’s easier said than done! One tactic is to use herbs and spices instead of salt in your meal. If you enjoy the food you eat, you’ll feel less restricted. Once you get the hang of mixing herbs and spices, you may want to keep shakers on the table and by the stove to supplement your cooking. The spices will enhance the flavor of the food, and you won’t miss the salt!
High-Sodium Foods to Stay Away From
- Potato chips with salt
- Canned or processed vegetables
- Frozen vegetables or prepared veggie meals with cheese, soy sauce, cream, butter, or garlic sauce
- Packaged, sliced, sandwich meats/cold cuts
- Frozen or commercially prepared marinades or dressings
Low-Sodium Foods to Use as Substitutes
- Carrot sticks with lemon and dill
- Fresh vegetables
- Plain frozen vegetables, cooked at home with spices and seasonings, and without added salt
- Homemade salad dressings, marinades, stocks
The Three Ps
There are three Ps to pay special attention to when fighting kidney disease: Phosphorus, Potassium, and Protein. Control of each can help reduce your risk of kidney failure, the need for visits to the dialysis center, or for a kidney transplant. Stage 3 CKD patients must consider the three Ps at each meal.
It’s challenging to know which foods have phosphorus and which don’t. You won’t often find labels that show the phosphorus content of the food you’d like to eat. So it is up to you to educate yourself and learn which foods are likely to have phosphorus. As a rule, it’s a good idea to stay away from sodas or any dark colas and any foods containing a high amount of dairy products.
Phosphorus “hides” in packaged foods. Learn to look for phosphorus in the list of ingredients on canned, bottled, boxed, or bagged food items. It won’t be on the label where you see calories, fat, sugar, sodium, and potassium. Instead, it will be listed in the ingredients. Anything that has “phos” in it means there’s phosphorus in it. So, beware of phosphoric, phosphate, etc.
High-Phosphorus Foods to Stay Away From
- Any sodas or dark colas, all canned & bottled drinks with phosphate additives, hot chocolate
- Dairy: Milk or cheese
- Nut butter: almond, peanut, etc.
- Meats, fish, and poultry, especially if excessively processed or cured
- French fries, potato chips, baked or mashed potatoes
- Chocolate candy bar
- Flavored waters, iced tea, non-dairy creamers, commercial punches, and orange juice substitutes, as well as other bottled items, often hide phosphate additives.
Low-Phosphorus Foods to Use as Substitutes
- Homemade iced tea, lemon and lime sodas, apple cider, root beer (only some brands omit phosphorus)
- Rice milk (unenriched), non-dairy creamer
- White carbs like pasta, white rice, couscous, white bread
- Butter or jams and jellies
- Fresh fish or poultry; or limited amounts of fresh or frozen meats prepared with marinades instead of salt
- Soaked or boiled potatoes to reduce potassium (Note: these are not considered low-potassium but are lower in potassium than potatoes that are not leached.)
- Lollipop without chocolate center
Taking phosphate binders with meals and snacks can help lessen the detrimental effects of phosphorus in your diet. Make sure you discuss this with your doctor and dietitian.
If your doctor indicates that your potassium intake is too high, you can reduce it with the proper diet. Limit your intake of foods with high potassium levels including dairy products, potatoes, nuts and seeds, beans, peanut, and almond butter, dried fruits, avocados, bananas, cantaloupes, kiwi, mangos, oranges. Watch out for foods that have potassium added. Sometimes potassium hides as the ingredient potassium chloride. Stay away from fruit and vegetable juices, and from consuming large quantities of spinach, tomatoes, squash, or pumpkins.
IMPORTANT NOTE: Chewing tobacco can cause spikes in potassium.
High-Potassium Foods to Stay Away From
- Bananas, cantaloupe, honeydew, kiwi, oranges, papaya
- Tomatoes, tomato sauce, spaghetti sauce, or chili sauce
- Baked potato or french fries
- Chocolate desserts
Low-Potassium Foods to Use as Substitutes
- Apples, berries, grapes, peaches, or pineapple
- Onions, bell peppers, mushrooms (small quantities), and garlic
- Mashed potatoes, boiled potatoes, or hash browns (all must be soaked and boiled to reduce potassium). Note: these are not considered low-potassium but are lower in potassium than potatoes that are not leached.
- Vanilla or lemon-flavored desserts
It’s a good idea to replace the animal protein in your diet with more plant-based substitutes such as legumes, nuts, tofu, grains, and seitan. However, if you are going to have animal proteins, an excellent source comes from egg whites and fish like salmon, tuna, and trout.
Since we’re talking about animal protein, now is an excellent time to understand the importance of monitoring fat intake in your diet. It’s a good idea to watch the amount of animal fat in your diet and to begin replacing animal fats with healthy alternatives such as olive oils and trans-fat-free spreads.
In the later stages of kidney disease, and especially if kidneys fail, it is often advised to limit your fluid intake. This sounds counter-intuitive since you’ve probably been advised to drink more water to hydrate yourself for most of your life. It isn’t easy to limit your water intake. Limiting your water intake is more than just drinking less water. It means consuming less soup, drinks, sauces, fruits, etc. If you haven’t already begun eating less salt, now is a good time to put this into practice because it will help to stave off your thirst. Your dietitian will help you learn how to satiate yourself when you are limiting water intake.
The best foods for kidney disease patients are the foods you and your medical team have decided are best for you. Keep a journal of the foods you eat you eat and their nutrient counts. Maintain a healthy weight. Work with your doctor to chart the results.
Chronic kidney disease, even at Stage 3, doesn’t necessarily mean you’re on your way to kidney failure and future visits to the dialysis center. But you must do everything you can to keep your chronic kidney disease CKD in check and reduce further kidney damage.
Actively managing your kidney diet is part of fighting chronic kidney disease!