24/03/2023
If you have kidney disease, it’s important to watch your intake of sodium, potassium, and phosphorus. Items that contain high amounts include cola, brown rice, bananas, processed meats, and dried fruits.
Your kidneys are bean-shaped organs that perform many important functions.
They’re in charge of filtering blood, removing waste through urine, producing hormones, balancing minerals, and maintaining fluid balance.
There are many risk factors for kidney disease. The most common are unmanaged diabetes and high blood pressure.
Alcoholism, heart disease, hepatitis C, and HIV are also causes of kidney disease (1Trusted Source).
When the kidneys become damaged and are unable to function properly, fluid can build up in the body and waste can accumulate in the blood.
However, avoiding or limiting certain foods in your diet may help decrease the accumulation of waste products in the blood, improve kidney function, and prevent further damage (2Trusted Source).
Diet and kidney disease
Dietary restrictions vary depending on the 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 disease, or kidney failure.
Those with end stage renal disease who require dialysis will also have varying dietary restrictions. Dialysis is a type of treatment that removes extra water and filters waste.
The majority of those with late or end stage kidney disease will need to follow a kidney-friendly diet to avoid a buildup of certain chemicals or nutrients in the blood.
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.
A kidney-friendly diet, or renal diet, usually limits sodium to under 2,300 mg per day, as well as your potassium and phosphorus intake.
The National Kidney Foundation’s most recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines don’t set specific limits on potassium or phosphorus (3).
Potassium and phosphorus are still a concern for people with kidney disease, but they should work closely with their 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 stages 3–5, should limit the amount of protein in their diets unless they’re on dialysis (3, 4Trusted Source).
However, those with end stage renal disease undergoing dialysis have an increased protein requirement (5Trusted Source).
Here are 17 foods that you should likely avoid on a renal 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 to a greater extent than natural, animal-based, or plant-based phosphorus (6Trusted Source).
Unlike natural phosphorus, phosphorus in the form of additives is not bound to protein. Rather, it’s found in the form of salt and highly absorbable by the intestinal tract (7Trusted Source).
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 food label.
While additive phosphorus content varies depending on the type of soda, most dark-colored sodas are believed to contain 50–100 mg in a 200-mL serving (8Trusted Source).
According to the United States Department of Agriculture (USDA) food database, a 12-ounce cola contains 33.5 mg of phosphorus (9Trusted Source).
As a result, sodas, especially those that are dark, should be avoided on a renal diet.
SUMMARY
Dark-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 their heart-healthy fats, fiber, and antioxidants.
While avocados are usually a healthy addition to the diet, those with kidney disease may need to avoid them.
This is because avocados are a very rich source of potassium. One average-sized avocado provides a whopping 690 mg of potassium (10Trusted Source).
By reducing the portion size to one-fourth of an avocado, people with kidney disease can still include this food in their diets while also 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.
SUMMARY
Consider avoiding avocados on a renal diet if your doctor or nutritionist 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 (11Trusted Source).
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 decrease the sodium content by 33–80%, depending on the product (12Trusted Source).
SUMMARY
Canned foods are often high in sodium. Avoiding, limiting, or buying low sodium varieties is likely best to reduce your overall sodium consumption.
4. Whole wheat bread
Choosing the right bread can be confusing for individuals with kidney disease.
Often for healthy individuals, whole wheat bread is usually recommended over refined, white flour bread.
Whole wheat bread may be a more nutritious choice, 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.
For example, a 1-ounce (30-gram) serving of whole wheat bread contains about 57 mg of phosphorus and 69 mg of potassium. In comparison, white bread contains only 28 mg of both phosphorus and potassium (13Trusted Source, 14Trusted Source).
Eating one slice of whole wheat bread instead of two can help lower your potassium and phosphorus intake without having to give 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 (15Trusted Source).
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.
SUMMARY
White 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.
One cup of cooked brown rice contains 150 mg of phosphorus and 154 mg of potassium, while 1 cup of cooked white rice contains only 69 mg of phosphorus and 54 mg of potassium (16, 17).
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.
SUMMARY
Brown 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 they’re naturally low in sodium, 1 medium banana provides 422 mg of potassium (18).
If you have been instructed to limit your potassium intake, it may be difficult to do so if a banana is a daily staple.
Unfortunately, many other tropical fruits have high potassium contents as well.
However, pineapples contain substantially less potassium than other tropical fruits and can be a more suitable yet tasty alternative (19).
SUMMARY
Bananas 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 natural source of phosphorus and potassium and a good source of protein.
For example, 1 cup (240 mL) of whole milk provides 222 mg of phosphorus and 349 mg of potassium (20).
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, which can pull calcium from your bones. This can make your bones thin and weak over time and increase your risk of bone breakage or fracture (21Trusted Source).
Dairy products are also high in protein. One cup (240 mL) of whole milk provides about 8 grams of protein (20).
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.
SUMMARY
Dairy products contain high amounts of phosphorus, potassium, and protein and should be limited on a renal diet. Despite milk’s high calcium content, its phosphorus content may weaken bones in those wi
