Diabetes and Kidney Disease: Let Your Lab Results Guide Your Choices
Each condition has its own needs. But when combined, food restrictions may overlap, and everyday choices can become more complicated.
Medical Disclaimer: This article is for education only. It does not replace advice from your healthcare provider. Food, fluid, protein, potassium, and phosphorus needs differ from person to person. Ask your healthcare provider or dietitian before making major changes.
When Healthy Choices Become Confusing
Diabetes and chronic kidney disease are two different health problems.
Diabetes affects how the body handles glucose, also called blood sugar. Food choices, activity, medicine, and regular testing can help keep blood sugar within a safer range.
Chronic kidney disease, often called CKD, means the kidneys have been damaged over time. They cannot filter the blood as well as they should.
The kidneys remove waste and extra fluid. They also help balance sodium, potassium, phosphorus, and other minerals.
Diabetes is one of the leading causes of CKD. However, not everyone with diabetes develops kidney disease. Kidney disease can also have other causes.
Each condition has its own food needs.
A food that helps with blood sugar may contain too much potassium or phosphorus for someone with certain kidney problems. A food that is lower in potassium may contain enough carbohydrates to raise blood sugar.
For example:
Brown rice has fiber, but it contains more phosphorus and potassium than white rice.
Potatoes may be high in potassium and carbohydrates.
Beans provide fiber and protein, but they also contain carbohydrates, potassium, and phosphorus.
A large serving of meat may contain few carbohydrates, but it may provide more protein and phosphorus than the kidneys need.
This does not mean these foods are bad.
It means the person’s lab results, kidney function, medicines, and serving sizes must all be considered.
Your Lab Results Help Complete the Picture
Do not remove nutritious foods just because you have kidney disease.
Some people with CKD need to limit potassium. Others do not. Some need to watch phosphorus or protein. Others may have different needs.
Your lab results help your healthcare team decide what needs attention.
The two main kidney tests are called eGFR and UACR. These letters may look confusing, but each test answers a different question.
Chronic Kidney Disease Has Different Stages
CKD is divided into stages according to how well the kidneys filter blood. The eGFR helps identify the stage.
CKD stage | eGFR | Simple meaning |
Stage 1 | 90 or higher | Kidney filtering is normal or high, but another test shows kidney damage |
Stage 2 | 60–89 | Mild loss of kidney function with another sign of kidney damage |
Stage 3a | 45–59 | Mild to moderate loss of kidney function |
Stage 3b | 30–44 | Moderate to severe loss of kidney function |
Stage 4 | 15–29 | Severe loss of kidney function |
Stage 5 | Below 15 | Kidney failure; dialysis or a transplant may be needed |
An eGFR of 60 or higher does not prove that someone has CKD. In Stages 1 and 2, another sign of kidney damage must also be present. This might be albumin in the urine or a change seen on another kidney test.
CKD usually means that the abnormal result or kidney damage has lasted for at least three months. One unusual test result may need to be repeated.
The stage is important, but it is not the whole story. The healthcare provider will also consider UACR, potassium, phosphorus, blood pressure, blood sugar, medicines, and changes in results over time.
These Conditions Can Be Managed
Living with diabetes and kidney disease requires attention, but it does not require perfection.
These conditions can often be managed with medical care, appropriate food choices, medicine, and regular testing. Treatment may help protect the kidneys and slow further damage.
Learning what works takes time. New habits take patience and daily practice. There may be good days, difficult days, and days when the plan needs to change.
One meal or one imperfect day does not erase the progress already made. The goal is to keep learning, ask for help when it is needed, and return to the plan one choice at a time.
What Do the Tests Mean?
Test or result | Simple meaning | What it may change |
eGFR | Estimates how well the kidneys filter blood | Protein, medicine, fluid, and other parts of the care plan |
UACR | Checks whether albumin, a type of protein, is leaking into the urine | Blood sugar, blood pressure, medicine, and kidney protection |
Potassium | Shows whether potassium is too high, too low, or within range | Fruit, vegetables, beans, potatoes, and salt substitutes |
Phosphorus | Shows whether phosphorus is building up or is too low | Processed foods, dark cola, dairy products, meat, and phosphorus additives |
A1C or blood sugar | Shows how the body is handling glucose | Carbohydrate choices and serving sizes |
Blood pressure | Shows the pressure placed on blood vessels | Sodium choices, medicine, and kidney protection |
What About Blood BUN and Creatinine?
BUN and creatinine are blood tests commonly used to help evaluate kidney function.
BUN, or blood urea nitrogen, measures a waste product made when the body breaks down protein. The result can be affected by kidney function, dehydration, protein intake, bleeding, illness, and certain medicines.
Creatinine is a waste product that comes mainly from normal muscle activity. The kidneys remove it from the blood. The blood creatinine result is used to calculate the eGFR and may also be used to estimate creatinine clearance.
Providers review these blood results before prescribing certain medicines and antibiotics. When kidney function is reduced, some medicines can build up in the body and cause harm.
The provider may:
Lower the dose
Give the medicine less often
Check additional blood tests
Choose a different medicine
BUN and creatinine still provide important information. However, CKD is usually staged with the eGFR, along with other signs of kidney damage such as the UACR.
One test does not always tell the whole story.
Illness, dehydration, medicine changes, and other problems can affect results. Your healthcare provider may repeat a test before changing your care plan.
Stable kidney function may be checked every three to twelve months. Testing may be done more often when kidney disease is advanced, a medicine changes, a person becomes ill, or a kidney specialist orders it.
Ask when your next blood and urine tests are due.
Potassium and Phosphorus Must Stay in Balance
The body needs potassium and phosphorus. The goal is not to remove them completely.
The goal is to keep them within a safe range.
A person should not try to raise or lower either level without medical advice.
Why Potassium Levels Matter
Potassium helps the heart, muscles, and nerves work properly.
Too much potassium can disturb the heartbeat and may cause muscle weakness.
Too little potassium can also disturb the heartbeat and may cause weakness, cramps, or unusual tiredness.
A dangerously high or low potassium level can be life-threatening. Some people have few or no warning signs, so a blood test is important.
Chest pain, trouble breathing, fainting, a racing or irregular heartbeat, or sudden severe weakness requires immediate medical help.
Do not try to raise or lower potassium without medical advice.
When Potassium Is High
Your healthcare provider or dietitian may ask you to limit certain high-potassium foods.
These may include:
Bananas
Oranges and orange juice
Avocados
Tomatoes and tomato sauce
Potatoes
Cooked spinach
Dried fruit
Large servings of beans
Salt substitutes containing potassium chloride
Possible lower-potassium choices include:
Berries
Apples
Grapes
Cabbage
Cauliflower
Cucumbers
Bell peppers
Lettuce
Turnip roots
Chayote
Serving size still matters. Eating several servings of a lower-potassium food can add up.
When Potassium Is Low
Do not automatically avoid potassium-rich foods when your potassium is low.
A healthcare provider may recommend adding certain foods, changing a medicine, or taking a potassium supplement. The right treatment depends on what caused the low level.
Too little potassium can also be dangerous.
Why Phosphorus Levels Matter
Phosphorus helps build strong bones and teeth. It also helps the body make energy.
When damaged kidneys cannot remove enough phosphorus, the level may rise.
Too much phosphorus can pull calcium from the bones. Over time, this can weaken bones and harm blood vessels.
Too little phosphorus can also weaken bones and muscles.
Do not try to raise or lower phosphorus without medical advice.
When Phosphorus Is High
Some phosphorus in food occurs naturally. Phosphorus is also added to many processed foods. The body absorbs added phosphorus very easily.
When phosphorus is high, ask whether you should limit:
Processed meats
Bacon and sausage
Processed cheese
Dark cola
Fast food
Packaged meals
Foods containing phosphorus additives
On an ingredient list, phosphorus additives often contain the letters “phos.”
Examples include:
Phosphoric acid
Sodium phosphate
Calcium phosphate
Potassium phosphate
Pyrophosphate
Fresh foods without phosphorus additives may be easier to fit into the plan.
Protein Needs Are Personal
Protein helps maintain muscles, heal wounds, and support the immune system.
However, breaking down protein creates waste that the kidneys must remove.
Protein needs depend on:
Body weight
Kidney function
The amount of protein in the urine
Age
Nutrition
Other health problems
Whether the person receives dialysis.
What If Protein Is Found in the Urine?
The UACR test checks whether albumin, a type of protein, is leaking from the blood into the urine.
Protein in the urine may mean that the kidney filters have been damaged. It does not mean the person should eat extra protein to replace what is being lost.
A large amount of dietary protein may increase the kidneys’ workload. Too little protein, however, can lead to poor nutrition and loss of muscle.
When protein is found in the urine, the healthcare provider or dietitian may adjust the amount or type of protein in the food plan. Treatment may also include better blood sugar control, blood pressure control, and prescribed medicine to help protect the kidneys.
For many adults with CKD who are not receiving dialysis, a healthcare provider may suggest about 0.8 grams of protein per kilogram of body weight each day. This amount is not right for everyone. People receiving dialysis often need more protein.
To change pounds into kilograms, divide the weight by 2.2.
For example:
180 pounds ÷ 2.2 = about 82 kilograms
82 × 0.8 = about 66 grams of protein per day
This is only an example. A provider or dietitian may use a different weight or protein goal when making the calculation.
Do not add extra protein or greatly lower protein because of a urine test without asking your healthcare provider or kidney dietitian.
Preparation and Portion Size Do Different Jobs
Some vegetables can be prepared in ways that remove part of their potassium.
Potatoes are a good example.
One Way to Lower Potassium in Potatoes
Peel the potatoes.
Cut them into small, thin pieces.
Rinse them.
Soak them in warm, unsalted water for at least two hours.
Use about 10 cups of water for every cup of potatoes.
Drain and rinse them again.
Boil them in fresh, unsalted water.
Drain and throw away the cooking water.
Do not use the cooking water in soup, sauce, or gravy.
This method lowers some of the potassium, but it does not remove all of it.
It also does not remove most of the carbohydrates.
For someone managing both diabetes and CKD:
Soaking and boiling may lower some potassium.
A smaller serving lowers both potassium and carbohydrates.
Lab results help determine whether potatoes fit the meal plan.
One Serving, Three Choices
These are approximate amounts in ½ cup cooked plain.
Vegetable | Vegetable | Potassium | Phosphorus | Total carbs |
Potato, boiled normally | Boiled potato, peeled | About 256 mg | About 31 mg | About 16 g |
Turnip root | Boiled turnip root | About 138 mg | About 20 mg | About 4 g |
Chayote | Boiled chayote | About 138 mg | About 23 mg | About 4 g |
Turnips and chayote contain fewer carbohydrates and less potassium than an ordinary boiled potato. This may make them easier to fit into meals for someone managing both diabetes and kidney disease.
The right choice still depends on the person’s lab results and serving size.
These numbers are estimates. The variety, preparation method, and exact serving size can change them.
The potato numbers are for a normally boiled potato, not one prepared with the special soaking and boiling method.
What About Rice?
Rice contains potassium and phosphorus. The amounts differ between white and brown rice.
These are approximate amounts in ½ cup cooked rice.
Potassium | |||||
Type of rice | Rice | Potassium | Phosphorus | Total carbs | |
White rice | About 25–30 mg | White, long-grain | About 28 mg | About 34 mg | About 22 g |
Brown rice | About 75–80 mg | Brown, long-grain | About 42 mg | About 81 mg | About 22 g |
Brown, medium-grain | About 77 mg | About 75 mg | About 23 g |
White rice may fit some kidney limits more easily because it contains less potassium and phosphorus.
However, both kinds contain about 22 to 23 grams of carbohydrates in only ½ cup.
Brown rice contains more fiber, but the carbohydrates still count.
How Is White Rice Made?
White rice is brown rice with the bran and germ removed. This leaves it with less fiber and fewer nutrients. It also lowers the potassium and phosphorus.
White rice may fit some kidney limits better, but it is still high in carbohydrates and can raise blood sugar. Serving size matters.
This is a good example of why food choices can become confusing. A food may fit one health need while creating a concern for another.
Lower-Carbohydrate Choices in Place of Rice
Rice is not the only choice.
Choice/Carbs Per Serving | How it can be used | What to remember |
Riced cauliflower About 1 g per ½ cup cooked | Sauté or microwave until tender | Low in carbohydrates and phosphorus, but contains more potassium than white rice |
Finely chopped cabbage About 1 g per ½ cup cooked | Sauté until soft and serve under saucy foods | Low in carbohydrates and usually easier to fit into many kidney meal plans |
Riced turnip root About 2½ g per ½ cup cooked | Grate or pulse in a food processor, then sauté | Lower in carbohydrates and potassium than potatoes |
Riced chayote About 2 g per ½ cup cooked | Grate, squeeze out extra moisture, and sauté | Mild flavor and lower in carbohydrates |
Riced zucchini About 2¼ g per ½ cup cooked | Grate, squeeze out extra water, and cook briefly | Low in carbohydrates, but potassium still counts |
Hearts-of-palm rice Varies by brand; check the package | Heat and use in place of rice | Packaged products may contain a lot of sodium |
Shirataki or konjac rice Varies by brand; check the package | Rinse well, drain, and heat | Very low in carbohydrates, but it may upset the stomach, and packaged products may contain sodium |
Rice and vegetable mixture About 11–12 g per ½ cup if made with ¼ cup cooked white rice and ¼ cup cabbage or cauliflower | Mix a small amount of white rice with cauliflower or cabbage | Keeps some rice texture while lowering the total carbohydrates |
A rice substitute may be lower in carbohydrates without being lower in potassium. The best choice depends on blood sugar goals and current kidney lab results.
Examples of Meals That May Fit Both Needs
These are examples, not meal plans. Portions and ingredients may need to change according to lab results.
Possible meals include:
A measured serving of baked chicken with sautéed cabbage and chayote
Baked fish with riced cauliflower and a cucumber salad
A vegetable omelet with peppers, onions, and cabbage
A small serving of meat with mashed turnips and a lower-potassium vegetable
Chicken or fish served over a mixture of white rice and riced cauliflower
A lettuce wrap filled with a measured serving of chicken or tuna
Sauces, seasoning blends, canned foods, and packaged products may add sodium, sugar, or phosphorus. The ingredient list and nutrition label can help uncover what has been added.
Over-the-Counter Medicines Matter Too
Food is not the only thing that affects the kidneys.
Some over-the-counter medicines and supplements can cause problems for people with CKD, diabetes, or high blood pressure.
Ask a healthcare provider or pharmacist before using:
NSAID pain relievers, including ibuprofen and naproxen
Cold medicines and decongestants, which may raise blood pressure
Antacids and laxatives, which may contain magnesium, aluminum, sodium, or phosphorus
Effervescent medicines, which may contain a large amount of sodium
Herbal products and supplements, which may affect the kidneys or interact with medicine
Salt substitutes, which may contain potassium chloride
Acetaminophen may be a safer pain-relief choice for some people with CKD when taken as directed. However, it is not right for everyone, especially people with certain liver problems or medicine interactions. Ask your doctor before using it regularly.
Do not stop a prescribed medicine without speaking with the healthcare provider who ordered it.
Ask for a Dietitian Who Understands Both Conditions
Ask your healthcare provider for a referral to a registered dietitian nutritionist who has experience with both diabetes and kidney disease.
Bring copies of your recent lab results. Also bring a list of:
Prescription medicines
Over-the-counter medicines
Vitamins
Minerals
Herbal products
Protein powders and nutrition drinks
The dietitian can help you understand which foods fit your current results, how much protein you may need, and which serving sizes may work for both conditions.
You should not have to piece together two different diets by yourself.
Let the Results Guide the Next Choice
Diabetes does not create one food plan for everyone.
Kidney disease does not create one food plan for everyone either.
A person with normal potassium does not always need a low-potassium diet. A person with normal phosphorus may not need to remove nutritious foods that contain phosphorus.
The plan may also change as lab results, medicines, and kidney function change.
Ask for copies of your results and keep them together. Bring them to medical and dietitian appointments.
The purpose is not to fear food. It is to make choices that match what your body needs now.
A Faithful Step
Managing two health problems can feel confusing. You may receive advice that seems to disagree.
You do not have to solve everything in one day.
Pray for wisdom. Ask questions. Seek help from people who understand both conditions. Then choose one useful step.
“If any of you lacks wisdom, you should ask God…”—James 1:5 NIV
That step may be requesting your lab results, making an appointment, checking a food label, or asking for a dietitian referral.
One faithful step can lead to another.
Would Support Make the Next Step Easier?
Faithful Steps health coaching can help you turn your healthcare provider’s and dietitian’s recommendations into small, realistic daily steps.
Coaching may help with planning meals, reading labels, building new habits, preparing questions for appointments, and staying encouraged when change feels difficult.
Health coaching does not diagnose illness, prescribe a kidney diet, or replace care from your healthcare provider or registered dietitian.
To learn more or schedule a free discovery call, visit FaithfulSteps.net.
Check the Studies Yourself
AI Transparency Note: This article was developed with the help of artificial intelligence for research, organization, and drafting. It was reviewed, edited, and approved by a retired registered nurse for clarity, accuracy, and usefulness.
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