Kidney stones are mineral deposits that form in the kidneys.
They can cause dull or sharp pain in your groin if they travel from your kidneys through your urinary tract.
If you have had kidney stones before, you’re significantly more likely to develop them again. However, you can decrease this risk by making changes to your diet.
This article explains what to eat and avoid with kidney stones to reduce their reoccurrence and provides a sample kidney stone diet menu.
Kidney stone types, symptoms, and risk factors
Nephrolithiasis, or kidney stones, is the most common condition affecting the urinary system, occurring in about 12% of the world’s population (1).
They form when the urine is highly concentrated with crystals, usually calcium oxalate or phosphate.
The other types of kidney stones may be composed of uric acid, struvite (magnesium ammonium phosphate), or cystine.
It’s possible to have kidney stones that contain more than one of these crystals.
Kidney stones vary in color and shape — depending on their type — and range in size from a grain of sand to a pearl, or sometimes larger (2).
Kidney stones present no signs or symptoms until they begin to travel from your kidneys through your urinary tract.
Symptoms of kidney stones may include (1):
- groin pain, which may be dull or sharp
- nausea and vomiting
- blood in your urine
- fever or chills, if the stones become infected
Various factors can increase the risk for kidney stones including:
- family history of kidney stones
- conditions that cause malabsorption like inflammatory bowel disease
- urinary tract infections
- low fluid intake
- high blood pressure
Kidney stone reoccurrence is common, with a 15% risk of developing them again within the first year, and 50% within the next ten years (1).
Recurrent stones may also increase the risk of developing chronic kidney disease or kidney failure.
Fortunately, you can reduce the risk of developing recurrent kidney stones by making changes to your diet.
Kidney stone diet
Calcium stones — including calcium oxalate and calcium phosphate stones — are the most common type of kidney stones, accounting for 80% of all stones worldwide (1).
As such, most studies have focused on dietary changes that reduce the risk or reoccurrence of calcium stones.
Here are the current best evidence-based dietary practices for reducing your risk of kidney stones (3):
- drink 2.5–3 liters (10–13 cups) of fluids daily
- consume 1,000–1,200 mg of calcium daily
- limit sodium to 2,300 mg or less daily
- limit processed meats
- eat more fruits and vegetables
Drinking more water has been shown to decrease the risk of developing kidney stones by 60–80% in both men and women (4).
This is because drinking more water increases urine flow, which lowers the concentration of crystals in the urine like calcium and uric acid that could otherwise build up and form kidney stones.
Clinical guidelines recommend drinking 2.5–3 liters (10–13 cups daily) to reduce the risk of kidney stones (5).
Beverages like coffee and tea can count towards this goal, with tea potentially offering protective benefits against kidney stone formation (6).
Adding fresh lemon juice to your water may also help decrease the risk of kidney stones (7).
Although it may seem counterintuitive to increase your calcium intake since most stones are composed of the mineral, doing so may help reduce your risk of developing kidney stones.
Calcium has a protective effect against kidney stone formation since it decreases the absorption of oxalate and therefore the formation of calcium oxalate kidney stones.
Clinical guidelines recommend consuming 1,000–1,200 mg of calcium daily to reduce the risk of kidney stones (3).
This amount is in line with the current calcium recommendations for overall health.
Good sources of calcium include (10):
- fortified orange juice
- fortified soy milk
- tofu or soybean products
If you struggle to get enough calcium from your diet, you can take calcium supplements — either as calcium citrate or carbonate — separated into two doses and ideally with meals.
Find calcium supplements online.
A higher sodium intake has been associated with up to a 61% increase in the risk of kidney stones (8).
However, the effect of sodium on calcium excretion may be offset with a higher fluid intake (8).
Still, limiting your sodium intake to 2,300 mg or less per day may be beneficial for decreasing kidney stone risk and overall health.
High-sodium foods to limit include:
- processed meats, such as bacon, hot dogs, and lunch meats
- snack foods, such as salted pretzels, chips, and nuts
- dairy products, including cottage cheese and buttermilk
- salted, canned products, such as soups or beans
- baking mixes
- boxed or frozen meals
- broths and gravies
- pickled vegetables, such as olives, pickles, or saurkraut
- sauces and condiments, such as ketchup, soy sauce, and hot sauce
- seasonings, such as salt, sea salt, garlic salt, and taco seasoning
- beverages, such as vegetable juice and sports drinks
Limit processed meats
A high intake of animal protein has been suggested to increase the risk of kidney stones by making the urine more acidic and increasing uric acid levels in the urine (11).
Animal proteins like seafood, meats, and poultry are high in purines, which the body metabolizes to uric acid.
But the current research isn’t strong enough to suggest that you need to eliminate or significantly restrict your intake of animal proteins to reduce your risk for kidney stones (8).
Still, it’s a good idea to limit your intake of processed meats, like lunch meats, bacon, ham, and salami, as these foods negatively impact kidney health and gut bacteria and are also rich in sodium.
Increase fruits and vegetables
Fruits and vegetables are alkaline-promoting foods, which help balance the acid-forming foods in your diet like protein.
This makes them especially beneficial for decreasing kidney stone risk as urine that is too acidic favors the formation of kidney stones.
In fact, one study found that eliminating fruits and vegetables increased the urinary concentration of calcium oxalate and phosphate urinary in healthy adults (12).
The same study also found that the inclusion of more fruits and vegetables in the diets of those with kidney stones didn’t affect urinary calcium levels but increased urine output and the excretion of minerals like potassium and magnesium, which help inhibit stone formation.
Some fruits and vegetables are rich in oxalates and may increase your risk for kidney stones, but assuming you’re getting enough calcium, watching your oxalate intake becomes less important.
This is especially true if you consume vegetables that are rich in both calcium and oxalate, such as turnip greens, kale, and bok choy.
3-day sample kidney stone diet menu
Here’s a 3-day sample kidney stone diet menu with a vegan option:
- Breakfast: an omelet and oatmeal cooked with milk and topped with berries
- Lunch: grilled chicken salad
- Snack: Greek yogurt, apple slices, and walnuts
- Dinner: grilled salmon with mixed grain salad
Day 2 (vegan)
- Breakfast: tofu scramble and glass of fortified orange juice
- Lunch: garbanzo bean salad
- Snack: vegan smoothie (soy milk, almond butter, chia seeds, frozen berries)
- Dinner: tofu tacos
- Breakfast: overnight oats
- Lunch: apple spinach salad with a diced hard-boiled egg
- Snack: low-sodium cottage cheese with fruit
- Dinner: grilled sardines with brown rice and broccolini
The bottom line
Kidney stones are the most common condition affecting the urinary system.
Of the four main types, calcium stones — including calcium oxalate and calcium phosphate stones — are the most common.
More than half of people who develop kidney stones are likely to develop them again over ten years.
You can reduce your risk of kidney stone reoccurrence by increasing your intake of fluids, calcium, and fruits and vegetables, and decreasing your intake of processed meats and other sodium-rich products.