Foods to Avoid for Kidney Stones

Spinach, rhubarb, and salty processed foods are among the main foods to limit for kidney stones, although the right restrictions depend on the type of stone and your urine test results.

Food changes are mainly intended to help prevent new kidney stones; they are not a substitute for assessment or treatment of a stone you have now. Ask your clinician whether your stone has been analyzed and whether you need a urine evaluation before making major dietary changes.

Fluids are also important for prevention. For more on drink choices, see the best drinks for kidney stones.

Which 7 foods should you limit for kidney stones?

These foods do not pose the same risk for everyone. Spinach, rhubarb, beets, and almonds matter most when you form calcium oxalate kidney stones and need to reduce oxalate; sodium and animal protein may be relevant to other stone-formers as well.

For adults with kidney stones, the American Urological Association recommends drinking enough fluid to produce at least 2.5 liters of urine per day. Use the water intake tool to estimate a starting drinking goal, then discuss it with your clinician; the amount you need to drink varies, and some people must restrict fluids.

1. Spinach

Spinach is high in oxalate. Oxalate can combine with calcium in urine, contributing to calcium oxalate kidney stones, particularly in people whose urine contains too much oxalate.

If you have been advised to lower oxalate, use spinach less often and choose a lower-oxalate leafy vegetable, such as lettuce, in salads or cooked dishes. Avoid relying on large spinach smoothies as an everyday source of greens. You do not necessarily need to avoid every food containing oxalate.

The evidence is strongest for managing the overall risk profile, rather than proving that removing spinach alone prevents kidney stones. A review of dietary oxalate and kidney stones supports limiting oxalate-rich foods and consuming adequate calcium for people at risk of calcium oxalate stones.

2. Rhubarb

Rhubarb is another high-oxalate food, so frequent rhubarb dishes can make it harder to reduce dietary oxalate. This concern is most relevant to calcium oxalate kidney stones, not automatically to every stone type.

If your clinician recommends a lower-oxalate diet, make rhubarb an occasional choice rather than a regular ingredient in pies, sauces, or desserts. Other fruits can provide variety without making rhubarb a staple; there is no need to remove fruit as a whole food group.

The evidence for limiting oxalate-rich foods comes from research on oxalate intake and urinary oxalate, summarized in the review above. It does not establish how much an individual serving of rhubarb changes any one person's risk.

3. Salty processed foods

High sodium intake can increase the amount of calcium excreted in urine, which may raise the risk of calcium kidney stones. Packaged snacks, deli meats, canned soups, and restaurant meals can contribute substantial sodium, even when they do not taste especially salty.

Compare the sodium values on food labels, choose lower-sodium versions when practical, and use herbs or other seasonings instead of adding as much salt. Look at the total for the day rather than treating one food as the entire problem.

For adults with calcium kidney stones and high urinary calcium, the American Urological Association recommends limiting sodium and consuming adequate dietary calcium; its sodium target is 2,300 milligrams per day. A review of high urinary calcium supports a lower-sodium diet as part of an individualized prevention plan, rather than as a stand-alone cure.

4. Beets

Beets contain oxalate, which can contribute to urinary oxalate. Like spinach and rhubarb, they are most relevant to people with calcium oxalate kidney stones who have been advised to reduce oxalate intake.

If beets are a frequent side dish or salad ingredient, substitute other vegetables more often. A varied diet can still include plenty of vegetables; the aim is to avoid repeatedly concentrating on high-oxalate choices, not to eliminate produce.

The evidence supports attention to overall oxalate exposure, but it does not show that avoiding beets alone prevents kidney stones. Your clinician or a registered dietitian can help decide whether beets need to be restricted based on your stone type and urine results.

5. Almonds

Almonds are high in oxalate, so almond-heavy snacks, almond flour, and almond butter may add up for someone trying to lower oxalate intake. The concern is the oxalate they contribute, not a claim that all nuts cause kidney stones.

If you need a lower-oxalate diet, use almond-based foods less frequently and ask a dietitian about alternatives that fit your nutritional needs. Check mixed foods as well: an ingredient such as almond flour may be less obvious than a handful of almonds.

The evidence is based on the role of dietary oxalate in calcium oxalate kidney stones, not on a trial showing that excluding almonds alone prevents recurrence. The appropriate restriction depends on the rest of your diet and your urine results.

6. Red meat and organ meats

Large amounts of animal protein can affect urine chemistry in ways that favor some kidney stones. Organ meats are also high in purines, which can increase uric acid production and matter for people prone to uric acid kidney stones.

Avoid making large portions of red or organ meat the center of every meal. Your clinician or dietitian can help you plan appropriate protein portions and alternatives; poultry and fish also count as animal protein, so switching meats alone may not address an excessive total intake.

A nutrition review describes animal protein as one of several dietary factors that can affect urinary stone risk. The evidence supports a balanced, individualized approach rather than eliminating all animal protein or using one meat restriction for every stone type.

7. Sweets and foods high in added sugar

A diet high in added sugar can make it harder to maintain a balanced eating pattern. Fructose intake has also been associated with kidney stones in observational research, although an association does not prove that one sweet food causes a stone.

Check labels on desserts, candies, and sweetened foods, and make them occasional choices rather than dietary staples. You do not need to avoid whole fruit simply because it contains natural sugar; ask for individualized advice if you have another condition that affects your diet.

A 2024 umbrella review of meta-analyses reported an association between fructose intake and kidney stones. That finding is less direct than evidence from a trial showing that removing a particular sweet prevents recurrence.

How should you adjust foods for your type of kidney stone?

Calcium oxalate kidney stones: Ask whether your urinary oxalate or calcium is high before making broad restrictions. If you need to reduce oxalate, focus first on foods you eat frequently that are high in it. Keep adequate calcium in your diet: calcium eaten with an oxalate-containing meal can bind some oxalate in the gut, reducing its absorption.

For adults with calcium kidney stones and high urinary calcium, the American Urological Association recommends 1,000–1,200 milligrams of dietary calcium per day. Do not assume that calcium-containing foods should be avoided because a stone contains calcium. Discuss calcium supplements with your clinician rather than starting or stopping them on your own.

Uric acid kidney stones: Protein intake and urine chemistry may need attention, but a low-oxalate diet is not automatically the answer. Your clinician can interpret urine testing and advise whether dietary changes, medication, or both are appropriate.

Other kidney stones: Cystine and infection-related kidney stones require different assessment and management. Restricting spinach or salt alone is not a substitute for a plan tailored to the stone type. If you pass a stone, ask whether it can be collected for analysis.

Who should be careful, and when should you see a doctor?

Seek urgent medical care if you have a suspected kidney stone with fever or chills, severe or worsening pain, persistent vomiting, or trouble passing urine. These symptoms can signal a complication that needs prompt assessment. Contact a clinician about blood in your urine, even if you think a kidney stone is the cause.

People with kidney disease, heart failure, or a prescribed fluid restriction should get individualized advice before increasing fluids. Children and pregnant people with suspected kidney stones also need medical assessment rather than a self-directed prevention diet.

If you take prescription medicines or calcium or vitamin C supplements, review them with your clinician before making changes. Do not stop prescribed medication on your own. A clinician can also advise whether stone analysis, blood tests, or a 24-hour urine collection would help guide prevention.