Foods to Avoid if You Have Kidney Stones

October 28, 2025 •

4 min read

Approximately 1 in 10 people will develop kidney stones in their lifetime, but dietary changes are one of the most effective ways to manage the condition. Knowing what foods to avoid if you have kidney stones is a critical step in preventing their recurrence and minimizing discomfort.

Quick Summary

This guide details the specific foods and dietary habits that increase the risk of kidney stone formation, organized by stone type. It covers high-oxalate foods, sodium intake, animal protein, and sugary drinks, with practical tips for making safer choices.

Key Points

High-Oxalate Foods: Reduce intake of spinach, rhubarb, nuts, and chocolate to help prevent calcium oxalate stones.
Excessive Sodium: Limit processed foods, fast food, and canned items to decrease urinary calcium levels, a key factor in stone formation.
Animal Protein: Moderate your consumption of red meat, organ meats, and shellfish to help control uric acid levels.
Sugary Drinks: Avoid or limit sodas, sweetened teas, and other sugary beverages, especially those with high-fructose corn syrup, which can promote stone growth.
Vitamin Supplements: Be cautious with high-dose Vitamin C or calcium supplements, as they may increase your risk of stones.
Prioritize Hydration: Drinking plenty of water is the single most important step for diluting stone-forming substances in your urine.

High-Oxalate Foods to Limit

For those who experience calcium oxalate stones, the most common type, reducing oxalate intake is a key strategy. Oxalate is a natural compound found in many plant-based foods that can bind with calcium in the urine to form crystals. While you don't need to eliminate all oxalate, being mindful of the highest-oxalate foods is essential.

Spinach and Rhubarb: These leafy greens are among the highest in oxalate and should be significantly limited or avoided.
Nuts and Nut Butters: Almonds, cashews, peanuts, and walnuts contain high levels of oxalate. Portion control is necessary, and pairing them with a calcium source can help.
Beets and Sweet Potatoes: Both of these vegetables have a high oxalate content.
Chocolate and Cocoa: The oxalate in these treats means they should be enjoyed in moderation.
Wheat Bran: Found in some cereals and baked goods, wheat bran is very high in oxalate.
Black Tea: The oxalate content in black tea can contribute to stone formation, and it is best to limit consumption.

Reducing Sodium and Processed Foods

Excessive sodium intake is a major contributor to kidney stone formation because it increases the amount of calcium that is excreted in the urine. This elevated urinary calcium makes it easier for stones to crystallize. Limiting your daily sodium intake to less than 2,300 mg is often recommended.

Processed and Packaged Foods: Canned soups, packaged meats (deli meat, sausages), frozen dinners, and salty snacks are loaded with sodium.
Fast Food and Restaurant Meals: Many items from fast-food chains and restaurants are notoriously high in sodium. Consider asking for sauces on the side and avoiding heavily salted dishes.
Condiments and Sauces: Ketchup, soy sauce, salad dressings, and certain gravies can hide significant amounts of salt. Look for low-sodium alternatives.
Pickled and Cured Items: Pickles, olives, and relish are preserved with salt and should be limited.

Moderating Animal Protein and Purine-Rich Foods

Eating a diet very high in animal protein, particularly red meat, poultry, eggs, and shellfish, can increase the risk of both calcium oxalate and uric acid stones. A high protein load can increase the amount of uric acid and calcium in your urine while also decreasing citrate, a chemical that helps prevent stone formation.

For those with uric acid stones, high-purine foods should be especially limited, as the body breaks down purines into uric acid.

High-Purine Animal Proteins: Red meat, organ meats (liver), sardines, and anchovies are high in purines.
Excessive Amounts of Other Animal Protein: While not as high in purines, overconsumption of chicken, eggs, and seafood should be moderated. Aim for moderate portions of animal protein and incorporate more plant-based protein sources, such as beans, lentils, and peas.

Comparison Table: Stone-Forming Foods vs. Safer Alternatives


Food Category	High-Risk Choices (to Avoid/Limit)	Safer Alternatives (to Include)
Oxalate-Rich	Spinach, rhubarb, beets, almonds, chocolate	Cauliflower, cucumbers, bananas, apples, low-fat milk
High-Sodium	Canned soup, deli meat, fast food, pickles	Fresh fruits and vegetables, homemade unsalted broth, fresh herbs and spices
Animal Protein	Red meat, organ meats, excessive poultry	Plant-based proteins (lentils, beans), moderate portions of fish
Sugary Drinks	Colas, sweet tea, fruit juices with added sugar	Plain water, sugar-free lemonade, plain water with fresh lemon
Supplements	High-dose Vitamin C or D supplements, calcium supplements	Obtain calcium from food sources; consult a doctor before taking supplements

The Problem with Sugary Drinks and Supplements

Sugary drinks, especially those containing high-fructose corn syrup, can increase the risk of kidney stones. Fructose can increase calcium and oxalate excretion in the urine, creating an ideal environment for stones to form. Dark-colored sodas, particularly colas, also contain phosphoric acid, which can contribute to stone formation.

Additionally, be cautious with certain supplements. High doses of Vitamin C supplements (over 500mg) can cause the body to produce more oxalate. Excess calcium supplements, as opposed to dietary calcium, have also been linked to an increased risk of stones. It is always best to consult a healthcare professional before starting any new supplement regimen.

Conclusion

Managing a kidney stone-prone diet is about making informed choices rather than simply restricting everything. By focusing on limiting high-oxalate foods, reducing sodium and animal protein intake, and avoiding sugary drinks, you can significantly lower your risk of recurrence. Proper hydration, along with these dietary adjustments, is your most powerful tool in managing this condition. Always remember to consult with a doctor or dietitian to create a personalized plan tailored to your specific needs and stone type, ensuring you maintain a balanced and healthy diet.

Visit the National Kidney Foundation for more resources on diet and kidney stone prevention.

Frequently Asked Questions

No, you should not avoid calcium. Dietary calcium actually helps prevent stones by binding with oxalate in the intestines before it reaches the kidneys. A diet too low in calcium can cause oxalate levels to rise, increasing stone risk. Focus on getting calcium from food, not supplements, unless advised by a doctor.

You should aim for enough fluid to produce about 2 to 3 liters (roughly 8 to 12 glasses) of urine per day. This dilutes stone-forming substances. Your urine should be light and clear, not dark yellow.

Moderate consumption of coffee and tea is generally acceptable, as some studies even show a protective effect. However, black tea is high in oxalates and should be limited if you form calcium oxalate stones.

A common mistake is drastically cutting out calcium from their diet, based on the name 'calcium oxalate stones'. This is counterproductive and can increase risk. The biggest culprit is often high sodium intake, which increases urinary calcium.

Fruits high in oxalates include raspberries, blackberries, strawberries, and dried figs. However, many common fruits like apples, bananas, and melons are low in oxalates.

Most nuts, including almonds, cashews, and peanuts, are high in oxalates. You don't need to eliminate them completely, but eat them in moderation and consider pairing them with a calcium source like cheese or yogurt.

Consider plant-based proteins such as lentils, beans, peas, and tofu. For animal protein, opt for moderate portions of skinless chicken or freshwater fish over organ meats and shellfish.