If you have kidney disease, it’s important to watch your intake of sodium, potassium, and phosphorus. Foods that contain high amounts include cola, brown rice, bananas, processed meats, and dried fruits.
Your kidneys perform many important functions, including:
- filtering your blood
- removing waste through urine
- producing hormones
- balancing minerals
- maintaining fluid balance (1)
When your kidneys become damaged and cannot function properly, fluid can build up in your body, and waste can accumulate in your blood.
Following a kidney-friendly diet and avoiding or limiting certain foods can help decrease the accumulation of waste products in your blood, improve your kidney function, and prevent further damage (3).
Here are 17 foods you should try to limit or avoid on a kidney diet.
1. Dark-colored soda
In addition to the calories and sugar that sodas provide, they harbor additives that contain phosphorus, especially dark-colored sodas.
Many food and beverage manufacturers add phosphorus during processing to enhance flavor, prolong shelf life, and prevent discoloration.
Your body absorbs this added phosphorus more than natural, animal-based, or plant-based phosphorus (9).
Unlike natural phosphorus, phosphorus in the form of additives is not bound to protein. Rather, it’s found in the form of salt and is highly absorbable by the intestinal tract (9).
Additive phosphorus can typically be found in a product’s ingredient list. However, food manufacturers are not required to list the exact amount of additive phosphorus on the label.
While additive phosphorus content varies depending on the type of soda, a 12-ounce (oz) or 355 milliliters (mL) cola contains 33.5 mg of phosphorus (10).
As a result, sodas, especially those that are dark, should usually be avoided on a renal diet.
SummaryDark-colored sodas should be avoided on a renal diet, as they contain phosphorus in its additive form, which is highly absorbable by the human body.
2. Avocados
Avocados are often touted for their many nutritious qualities, including heart-healthy fats, fiber, and antioxidants.
While avocados are usually a healthy addition to the diet, they are considered one of the high-potassium foods to avoid with kidney disease.
In fact, one average-sized avocado provides a whopping 690 mg of potassium (11).
By reducing the portion size to one-fourth of an avocado, people with kidney disease can still include this food in their diets while limiting potassium, if needed.
Avocados, including guacamole, should be limited or avoided on a renal diet if you have been told to watch your potassium intake.
However, remember that different individuals have different needs, and your overall diet and health goals are the most important thing to consider.
SummaryConsider avoiding avocados on a renal diet if a doctor or dietitian has advised you to lower your potassium intake.
3. Canned foods
Canned foods such as soups, vegetables, and beans are often purchased because of their low cost and convenience.
However, most canned foods contain high amounts of sodium, as salt is added as a preservative to increase its shelf life (12).
Due to the amount of sodium found in canned goods, it’s often recommended that people with kidney disease avoid or limit their consumption.
Choosing lower sodium varieties or those labeled “no salt added” is typically best.
Additionally, draining and rinsing canned foods, such as canned beans and tuna, can significantly decrease the sodium content (13).
SummaryCanned foods are often high in sodium. Avoiding, limiting, or buying low sodium varieties is likely the best to reduce your overall sodium consumption.
4. Whole wheat bread
Choosing the right bread can be confusing for individuals with kidney disease.
For healthy individuals, whole wheat bread is usually recommended over refined, white flour bread.
Whole wheat bread may be more nutritious, mostly due to its higher fiber content. However, white bread is usually recommended over whole wheat varieties for individuals with kidney disease.
This is because of its phosphorus and potassium content. The more bran and whole grains in the bread, the higher the phosphorus and potassium contents (14).
For example, a regular slice, or 36-gram (g) serving, of whole wheat bread contains about 76 mg of phosphorus and 90 mg of potassium. In comparison, a regular slice (28 g) of white bread contains approximately 32 mg of phosphorus and potassium (15, 16).
Eating one slice of whole wheat bread instead of two can help lower your potassium and phosphorus intake without giving up whole wheat bread entirely.
Note that most bread and bread products, regardless of whether they’re white or whole wheat, also contain relatively high amounts of sodium (17).
It’s best to compare the nutrition labels of various types of bread, choose a lower sodium option if possible, and monitor your portion sizes.
SummaryWhite bread is typically recommended over whole wheat bread on a renal diet due to its lower phosphorus and potassium levels. All bread contains sodium, so it’s best to compare food labels and choose a lower-sodium variety.
5. Brown rice
Like whole wheat bread, brown rice is a whole grain that has a higher potassium and phosphorus content than its white rice counterpart.
Each cup (155 g) of cooked brown rice contains 149 mg of phosphorus and 95 mg of potassium, while 1 cup (186 g) of cooked white rice contains only 69 mg of phosphorus and 54 mg of potassium (18, 19).
You may be able to fit brown rice into a renal diet, but only if the portion is controlled and balanced with other foods to avoid an excessive daily intake of potassium and phosphorus.
Bulgur, buckwheat, pearled barley, and couscous are nutritious, lower-phosphorus grains that can make a good substitute for brown rice.
SummaryBrown rice has a high content of phosphorus and potassium and will likely need to be portion-controlled or limited on a renal diet. White rice, bulgur, buckwheat, and couscous are all good alternatives.
6. Bananas
Bananas are known for their high potassium content.
While naturally low in sodium, 1 medium banana provides 422 mg of potassium (20).
If you have been instructed to limit your potassium intake, it may not be easy if a banana is a daily staple.
Unfortunately, many other tropical fruits have high potassium content as well.
However, pineapples contain substantially less potassium than other tropical fruits and can be a more suitable yet tasty alternative (21).
SummaryBananas are a rich source of potassium and may need to be limited on a renal diet. Pineapple is a kidney-friendly fruit, as it contains much less potassium than certain other tropical fruits.
7. Dairy
Dairy products are rich in various vitamins and nutrients.
They’re also a high protein food and a natural source of phosphorus and potassium.
For example, 1 cup (240 mL) of whole milk provides 205 mg of phosphorus and 322 mg of potassium (22).
Yet, consuming too much dairy, in conjunction with other phosphorus-rich foods, can be detrimental to bone health in those with kidney disease.
This may sound surprising, as milk and dairy are often recommended for strong bones and muscle health.
However, when the kidneys are damaged, too much phosphorus consumption can cause a buildup of phosphorus in the blood, pulling calcium from your bones. This can make your bones thin and weak over time and increase your risk of bone breakage or fracture (23).
Dairy products are also high in protein. Each cup (240 mL) of whole milk provides nearly 8 g of protein (22).
It may be important to limit dairy intake to avoid the buildup of protein waste in the blood.
Dairy alternatives like unenriched rice milk and almond milk are much lower in potassium, phosphorus, and protein than cow’s milk, making them a good substitute for milk while on a renal diet.
SummaryDairy products contain high amounts of phosphorus, potassium, and protein and should be limited to a renal diet. Despite milk’s high calcium content, its phosphorus content may weaken bones in those with kidney disease.
8. Oranges and orange juice
While oranges and orange juice are arguably most well known for their vitamin C content, they’re also rich sources of potassium.
One large orange (184 g) provides 333 mg of potassium. Moreover, there are 458 mg of potassium in 1 cup (240 mL) of orange juice (24, 25).
Given their potassium content, oranges and orange juice likely need to be avoided or limited on a renal diet.
Grapes, apples, and cranberries, as well as their respective juices, are all good substitutes for oranges and orange juice, as they have lower potassium content.
SummaryOranges and orange juice are high in potassium and should be limited to a renal diet. Try grapes, apples, cranberries, or their juices instead.
9. Processed meats
Processed meats have long been associated with chronic diseases and are generally considered unhealthy due to their preservative contents (26, 27).
Processed meats are meats that have been salted, dried, cured, or canned.
Some examples include hot dogs, bacon, pepperoni, jerky, and sausage.
Processed meats typically contain large amounts of salt, mostly to improve their taste and preserve flavor (28).
Therefore, it may not be easy to keep your daily sodium intake to less than 2,300 mg if processed meats are abundant in your diet.
Additionally, processed meats are high in protein.
If you have been told to monitor your protein intake, it’s important to limit processed meats for this reason as well.
SummaryProcessed meats are high in salt and protein and should be consumed in moderation on a renal diet.
10. Pickles, olives, and relish
Pickles, processed olives, and relish are all examples of cured or pickled foods.
Usually, large amounts of salt are added during the curing or pickling process.
For example, one pickle spear can contain around 283 mg of sodium. Likewise, there are 244 mg of sodium in 2 tablespoons (30 g) of sweet pickle relish (29, 30).
Processed olives also tend to be salty, as they’re cured and fermented to taste less bitter. Five green pickled olives provide about 211 mg of sodium, a significant portion of the daily amount in only a small serving (31).
Many grocery stores stock reduced-sodium varieties of pickles, olives, and relish, which contain less sodium than their traditional counterparts.
However, even reduced sodium options can still be high in sodium, so you will still want to watch your portions.
SummaryPickles, processed olives, and relish are high in sodium and should be limited on a renal diet.
11. Apricots
Apricots are rich in vitamin C, vitamin A, and fiber.
They’re also high in potassium. Each cup (165 g) of fresh, sliced apricots provides 427 mg of potassium (32).
Furthermore, the potassium content is even more concentrated in dried apricots.
Just 1 cup (130 g) of dried apricots provides over 1,500 mg of potassium (33).
This means that just 1 cup of dried apricots provides 75% of the 2,000-mg low potassium restriction.
It’s best to avoid apricots and, most importantly, dried apricots on a renal diet.
SummaryApricots are a high potassium food that should be avoided on a renal diet. They offer over 400 mg per 1 cup (165 g) raw and over 1,500 mg per 1 cup (130 g) dried.
12. Potatoes and sweet potatoes
Potatoes and sweet potatoes are potassium-rich vegetables.
Just one medium-sized baked potato (156 g) contains 610 mg of potassium, whereas one average-sized baked sweet potato (114 g) contains 542 mg of potassium (34, 35).
Fortunately, some high-potassium foods, including potatoes and sweet potatoes, can be soaked or leached to reduce their potassium contents.
In fact, some research suggests that boiling potatoes can significantly decrease their potassium content, especially if you start with cold water (36).
Soaking potatoes in water for 5–10 minutes could also reduce potassium by up to 20% (37).
This method is known as potassium leaching or the double-cook method.
Although double-cooking potatoes lowers the potassium content, it’s important to remember that their potassium content isn’t eliminated by this method.
Considerable amounts of potassium can still be present in double-cooked potatoes, so it’s best to practice portion control to keep potassium levels in check.
SummaryPotatoes and sweet potatoes are high-potassium vegetables. Boiling or double-cooking potatoes can significantly reduce their potassium content.
13. Tomatoes
Tomatoes are another high-potassium fruit that may not fit the guidelines of a renal diet.
They can be served raw or stewed and are often used to make sauces.
Just 1 cup (245 g) of tomato sauce can contain 728 mg of potassium (38).
Though tomatoes are commonly used in many dishes, several substitutes are available.
Choosing an alternative with lower potassium content depends largely on your taste preferences. However, swapping tomato sauce for a roasted red pepper sauce can be equally delicious and provide less potassium per serving.
SummaryTomatoes are another high-potassium fruit that should likely be limited on a renal diet.
14. Packaged, instant, and premade meals
Processed foods can be a major component of sodium in the diet.
Among these foods, packaged, instant, and premade meals are usually the most heavily processed and thus contain the most sodium.
Examples include frozen pizza, microwaveable meals, and instant noodles.
Keeping sodium intake to 2,300 mg per day may be difficult if you’re eating highly processed foods regularly.
Heavily processed foods not only contain a large amount of sodium but also commonly lack nutrients (39).
SummaryPackaged, instant, and premade meals are highly processed items that can contain very large amounts of sodium and lack nutrients. It’s best to limit these foods on a renal diet.
15. Swiss chard, spinach, and beet greens
Swiss chard, spinach, and beet greens are leafy green vegetables with high amounts of nutrients and minerals, including potassium.
When served raw, the amount of potassium varies between 136–290 mg per cup (30–38 g) (40, 41, 42).
While leafy vegetables shrink to a smaller serving size when cooked, the potassium content remains unchanged.
For example, raw spinach can significantly shrink when cooked. Therefore, eating one-half cup of cooked spinach will contain a much higher amount of potassium than one-half cup of raw spinach.
Raw Swiss chard, spinach, and beet greens are preferable to cooked greens to avoid too much potassium.
However, moderate your intake of these foods, as they’re also high in oxalates. Among sensitive individuals, oxalates can increase the risk of kidney stones (43).
Kidney stones may further damage renal tissue and decrease kidney function.
SummaryLeafy green vegetables like Swiss chard, spinach, and beet greens are full of potassium, especially when served cooked. Although their serving sizes become smaller when cooked, their potassium contents remain the same.
16. Dates, raisins, and prunes
Dates, raisins, and prunes are common dried fruits.
When fruits are dried, their nutrients are concentrated. This includes potassium.
For example, 1 cup (174 g) of prunes provides 1,270 mg of potassium, which is nearly five times the amount of potassium found in 1 cup (165 g) of plums, its raw counterpart (44, 45).
Moreover, just four dates provide 668 mg of potassium (46).
Given the high amount of potassium in these common dried fruits, it’s best to go without them while on a renal diet to ensure your potassium levels remain favorable.
SummaryNutrients are concentrated when fruits are dried. Therefore, the potassium content of dried fruit, including dates, prunes, and raisins, is extremely high and should be avoided on a renal diet.
17. Pretzels, chips, and crackers
Ready-to-eat snack foods like pretzels, chips, and crackers tend to be lacking in nutrients and relatively high in salt.
Also, it’s easy to eat more than the recommended portion size of these foods, often leading to an even greater salt intake than intended.
What’s more, if chips are made from potatoes, they’ll contain a significant amount of potassium as well (47).
SummaryPretzels, chips, and crackers are easily consumed in large portions and tend to contain high amounts of salt. Additionally, chips made from potatoes provide a considerable amount of potassium.
Kidney-friendly recipes
Following a kidney-friendly diet requires limiting several foods, which can be challenging. However, there are many nutritious and delicious recipes that you can still enjoy as part of a balanced kidney diet.
Here are a few tasty options available from the National Kidney Foundation:
- Chicken and Zucchini Quiche
- Pumpkin Pancakes
- Mexican-Style Stuffed Peppers
Be sure to make adjustments as needed, depending on your specific needs and preferences.
A renal dietitian can also recommend kidney-friendly recipes to help round out your diet.
SummaryThere are many nutritious recipes available that can easily fit into a renal diet. You can also adjust recipes based on your needs and preferences.
How are dietary restrictions for kidney disease determined?
Your specific dietary restrictions will depend on your stage of kidney disease. For instance, people with early stages of chronic kidney disease will have different dietary restrictions than those with end-stage renal (kidney) disease or kidney failure.
Those with end-stage kidney disease who require dialysis also have varying dietary restrictions. Dialysis is a type of treatment that removes extra water and filters waste (4).
Most of those with late or end-stage kidney disease need to follow a kidney-friendly diet to avoid a buildup of certain chemicals or nutrients in the blood (5).
In those with chronic kidney disease, the kidneys cannot adequately remove excess sodium, potassium, or phosphorus. As a result, they’re at a higher risk of elevated blood levels of these minerals (5).
A kidney-friendly diet, or renal diet, usually limits sodium to under 2,300 milligrams (mg) per day, as well as your potassium and phosphorus intake (5).
The National Kidney Foundation’s most recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines don’t set specific limits on potassium or phosphorus (6).
Potassium and phosphorus are still a concern for people with kidney disease. Still, they should work closely with a doctor or dietitian to determine their personal limits for these nutrients, which are usually based on lab results.
Damaged kidneys may also have trouble filtering the waste products of protein metabolism. Therefore, individuals with chronic kidney disease of all stages, especially stage 3–5, should limit the amount of protein in their diets unless they’re on dialysis (6, 7).
However, those with end-stage kidney disease undergoing dialysis have an increased protein requirement (8).
Frequently asked questions
What foods help your kidneys work better?
The best thing you can do to help your kidneys work better is to eat a well-balanced diet full of nutritious, vitamin-rich foods that are low in sodium, potassium, and phosphorus (53).
Some examples include:
- tofu
- cheese that’s low in phosphorus (such as goat cheese, grated parmesan, mozzarella, Monterey Jack, Swiss cheese, and Brie)
- milk alternatives (such as oat, soy, or rice)
- healthy cooking oils (such as olive oil, safflower oil, or sesame oil)
- fish
- fresh fruit (like strawberries, blueberries, apples, pomegranates)
- beans
Is peanut butter good for the kidneys?
Peanut butter is a good source of plant-based protein. It’s naturally low in carbohydrates, and has plenty of fiber to aid digestion. It’s a good substitute for meat in a kidney diet plan.
However, it’s worth noting that 2 tablespoons of peanut butter also has 65 milligrams of oxalate, and high amounts of oxalate can contribute to kidney stones (54, 55). Talk with your doctor if you’re prone to kidney stones, as you may want avoid or reduce your peanut butter consumption.
Also, when purchasing peanut butter, be sure to look for brands that don’t add extra salt and sugar.
Is chocolate bad for the kidneys?
Dark chocolate is rich in antioxidants and has actually been shown to reduce certain markers of inflammation in people undergoing dialysis (50, 51).
Still, chocolate is high in calories and added sugar and contains some phosphorus and potassium. Therefore, it’s best to enjoy it in moderation as part of a well-rounded diet, especially if you have kidney disease (52).
Are eggs bad for the kidneys?
Eggs are highly nutritious and can often fit into a balanced renal diet. However, people following a low protein diet may need to moderate their intake, depending on the amount of protein that they are allotted each day (48).
Is coffee bad for the kidneys?
Enjoying the occasional cup of coffee is typically fine on a renal diet and is unlikely to affect kidney health.
However, drinking 3–4 cups (473–710 mL) daily or adding large amounts of milk, creamer, or flavored syrup may increase potassium or phosphorus levels. Additionally, drinking multiple cups is not recommended if you’ve been advised to restrict your fluid intake (49).
The bottom line
If you have kidney disease, reducing your potassium, phosphorus, and sodium intake can be an important aspect of managing the disease.
The high sodium, potassium, and phosphorus foods listed above are likely best limited or avoided.
Dietary restrictions and nutrient intake recommendations will vary based on the severity of your kidney damage.
Following a renal diet can seem daunting and a bit restrictive at times. However, working with a healthcare professional and renal dietitian can help you design a renal diet specific to your individual needs.