What not to eat in case of a kidney stone?

December 28, 2025 •

4 min read

As many as 1 in 10 people will experience a kidney stone in their lifetime, and certain dietary habits can significantly increase that risk. For those who have already dealt with the painful condition, knowing what foods to avoid is one of the most effective ways to prevent future recurrences and manage symptoms.

Quick Summary

An individual's diet can substantially impact kidney stone formation, with specific foods triggering crystal growth depending on the stone's type. Limiting high-oxalate foods, reducing excessive sodium and animal protein, and avoiding certain supplements are crucial steps to take. Dietary modifications are a key component of prevention and management.

Key Points

High-Oxalate Foods: Minimize your intake of spinach, rhubarb, nuts, beets, and chocolate if you have calcium oxalate stones.
Sodium Restriction: Limiting high-sodium processed foods, fast food, and canned goods helps reduce urinary calcium levels.
Animal Protein Moderation: Excessive intake of red meat, poultry, and eggs can increase uric acid, contributing to stone formation.
Beverage Choices: Avoid sugary sodas, drinks with high-fructose corn syrup, and excessive caffeine. Prioritize water and citrus drinks instead.
Supplements vs. Food: Get calcium and Vitamin C from food, not supplements, as high-dose supplements can increase kidney stone risk.
Crucial Hydration: Drinking plenty of water is the single most important step to prevent kidney stones by diluting minerals in the urine.

The Importance of Diet for Kidney Stone Prevention

Diet plays a crucial role in the formation and prevention of kidney stones. While the exact dietary modifications depend on the specific type of stone, some general rules apply across the board. The four main types of kidney stones are calcium oxalate, uric acid, struvite, and cystine. Calcium oxalate stones are the most common and are significantly influenced by dietary choices. Regardless of the stone type, staying well-hydrated is the most important step, as it dilutes the urine and prevents minerals from clumping together.

High-Oxalate Foods to Restrict

For individuals with calcium oxalate stones, limiting foods high in oxalate is critical. Oxalate is a compound that binds with calcium in the kidneys to form stones. Some common culprits to cut back on include:

Spinach and rhubarb
Nuts and nut products, especially almonds and cashews
Beets
Chocolate
Soy products, such as tofu
Sweet potatoes
Black tea

It is important to note that you do not need to eliminate calcium entirely. In fact, getting enough dietary calcium from food sources can help reduce the risk of stones by binding with oxalate in the digestive tract before it reaches the kidneys. Just be mindful of pairing oxalate-rich foods with calcium-rich ones and avoiding excessive calcium supplements.

Limiting Sodium and Animal Protein

Sodium, a key component of salt, can increase calcium levels in the urine and raise the risk of kidney stones. Most Americans consume more sodium than is recommended, and for those susceptible to kidney stones, monitoring intake is vital. Common sources of high sodium to avoid include processed foods, canned goods, fast food, and certain condiments.

For uric acid stone sufferers and other stone formers, limiting animal protein is also advised. Red meat, poultry, eggs, and shellfish contain purines, which increase uric acid levels in the urine. Replacing some animal protein with plant-based alternatives, such as legumes and lentils, can help.

Sugary and Caffeinated Drinks

Many beverages can increase the risk of kidney stones. Sugary drinks, particularly those sweetened with high-fructose corn syrup, can contribute to stone formation. Excessive consumption of caffeinated drinks, like coffee and tea, can also increase urinary oxalate levels. While moderate intake might be acceptable for some, staying hydrated with plain water and citrus-based drinks like lemonade is often recommended. Conversely, cola drinks contain high levels of phosphate, another mineral that can contribute to certain stone types.

A Deeper Look at Foods to Avoid: A Comparison Table

It is essential to understand which foods to limit based on common stone types. While these are general guidelines, a healthcare provider can offer personalized advice.


Food Category	Calcium Oxalate Stones	Uric Acid Stones	General Advice
High-Oxalate Items	AVOID/LIMIT: Spinach, rhubarb, beets, nuts, chocolate, bran cereal.	OK	Limit for calcium oxalate stones; eat with calcium-rich foods.
Animal Proteins	LIMIT: Beef, pork, poultry, eggs, fish.	AVOID/LIMIT: Red meat, organ meats, shellfish.	Limit intake to recommended daily amounts to reduce uric acid and overall risk.
High Sodium Foods	AVOID/LIMIT: Processed and canned foods, fast food, salty snacks.	AVOID/LIMIT	A high-sodium diet increases urinary calcium and overall stone risk.
Sugary Drinks	AVOID: High-fructose corn syrup sodas and juices.	AVOID: Sugary drinks and alcohol.	Can increase risk for various stone types and contribute to dehydration.
Supplements	CAUTION: Calcium and Vitamin C supplements.	CAUTION: Vitamin C supplements.	Get vitamins from food, as supplements can sometimes contribute to stone formation.

The Role of Hydration and Other Lifestyle Changes

While focusing on what to avoid is important, it is equally vital to prioritize healthy habits. The single most effective way to prevent kidney stones is to drink plenty of fluids throughout the day, aiming for at least 2 to 3 liters of urine output daily. Clear or pale-colored urine is a good indicator of adequate hydration. Staying active and maintaining a healthy weight also lowers your risk of recurrence. For some people, a combination of dietary changes and medication may be necessary to effectively manage and prevent stones. Consulting with a healthcare provider or a dietitian who specializes in renal issues is the best course of action for a personalized diet plan.

Conclusion

Understanding what not to eat is a powerful tool in managing and preventing kidney stones. By minimizing high-oxalate foods, reducing sodium and excessive animal protein, and cutting back on sugary and caffeinated drinks, you can take a proactive approach to your health. These dietary adjustments, when combined with proper hydration, form a strong defense against the painful experience of kidney stone recurrence. Always discuss any significant changes to your diet with a medical professional to ensure the plan is appropriate for your specific needs.

Learn more about managing your diet for kidney stones and other kidney health topics on the National Kidney Foundation's official website. National Kidney Foundation: 6 Easy Ways to Prevent Kidney Stones

Frequently Asked Questions

The worst foods to eat depend on the type of kidney stone. For calcium oxalate stones, high-oxalate foods like spinach, nuts, and chocolate are harmful. For uric acid stones, high-purine foods like red meat and shellfish should be limited. High sodium intake is problematic for most stone types.

No, you don't need to completely eliminate all oxalate. A better strategy is to eat a balanced diet and consume calcium-rich foods with your meals. Calcium from food binds to oxalate in the intestines, preventing it from being absorbed and forming stones in the kidneys.

No, drinking milk is not bad for kidney stones. Adequate calcium from food sources, including dairy, is essential and helps prevent stones. However, be cautious with calcium supplements, which can increase risk, and consult your doctor before taking them.

Aim for a fluid intake that allows you to pass about 2 to 3 liters of urine per day. This means drinking plenty of water throughout the day. Pale and clear urine is a good sign of proper hydration.

Yes, processed and canned foods are often high in sodium, which increases the amount of calcium in your urine and elevates your risk of forming kidney stones. It is best to choose fresh, low-sodium alternatives.

Excessive animal protein, including red meat, poultry, and fish, can increase uric acid levels and decrease citrate in your urine, which promotes stone formation. Limiting intake and opting for plant-based proteins can be beneficial.

Yes, high-dose vitamin C supplements (over 1,000 mg/day) have been linked to an increased risk of kidney stones. It is safer to get your daily vitamin C from food sources like fruits and vegetables.