Kidney Stones Diet: What To Eat and Avoid

If you’ve ever passed a kidney stone, we’ve got some bad news: There’s a high chance you’ll feel that intense pain again. Roughly 30% to 50% of people who’ve had a kidney stone can expect another within five years.

Want to prevent that? A good place to start is by taking a hard look at what you eat and drink.

Your daily menu can play a significant role in the formation of kidney stones, say urologists Jorge Gutierrez-Aceves, MD, and Smita De, MD, PhD.

Here’s what should and shouldn’t be on your plate to help keep your kidneys from turning into stone quarries.

How diet influences kidney stones

Kidney stones are hard deposits made of minerals and salts that collect in the kidneys. A kidney stone diet can limit the accumulation of stone-building materials that can eventually clump together to form stones.

“Kidney stones are a symptom of something happening in your kidney,” explains Dr. Gutierrez-Aceves. “What you eat and drink can either help guard against stones forming or contribute to their formation.”

Foods to emphasize

A steady diet of the following can help you avoid kidney stones.

Fluids

A glass may be your most effective tool to prevent kidney stones. “Staying hydrated by drinking plenty of fluids is the No. 1 thing you can do to keep stones from forming,” emphasizes Dr. Gutierrez-Aceves.

The reason? It’s all about urine production.

Your kidneys use urine to flush waste products from your body. If you’re not drinking enough, you pee less — and what comes out tends to be more concentrated. (You’ll notice that it’s darker in color.)

Low urine volume allows excess vitamins, salts, acids and other waste items to build up in your kidneys. Waste that lingers is more likely to bond together and form a crystal that will become a future stone.

You can limit your risk of kidney stones by drinking at least 96 to 110 ounces (roughly 3 liters) of fluid per day, says Dr. Gutierrez-Aceves. Add in a few extra glasses if you’re sweating a lot and losing fluid due to exercise or warmer temperatures.

Water is best, but almost anything you splash into a cup — including coffee and teas — works to help keep you hydrated and guard against kidney stones.

But try to limit sugary drinks (like punch and cola), which have been linked to kidney stone risk.

Citrus

Citrus fruit — lemons, limes and oranges in particular — serve as kryptonite for certain types of kidney stones. That’s because they contain citrate, which neutralizes acid in urine to stop stones from forming.

“Uric acid crystals form and turn into stones in an acidic environment,” explains Dr. De. “So, if your urine is alkaline [the opposite of acidic], then uric acid stones won’t form.”

And if you already have uric acid stones (there are several types of kidney stones), citrate naturally works to dissolve them. Citrus may also prevent the formation of other types of stones. (Good deal, right?)

Adding a spritz of lemon, lime or orange juice to water throughout the day is an easy and tasty way to boost your citrate. Plus, it’ll help keep you hydrated!

Calcium-rich foods

People who develop calcium oxalate stones, the most common type of kidney stones, often believe they need to eliminate dairy and other calcium-rich foods from their diet. That’s wrong and the opposite of what’s currently recommended.

Calcium can actually help reduce your risk of kidney stones by neutralizing oxalates in your gut. (We’ll get into that more in a bit.)

“It may seem a bit illogical, given that these stones are based on calcium, but there’s no reason to remove calcium from your diet,” says Dr. Gutierrez-Aceves. “Calcium in the diet is good and recommended — even if you have a history of kidney stones.”

But taking large amounts of calcium supplements can sometimes cause an issue. Try to meet your calcium needs through food rather than supplements, unless your doctor recommends otherwise.

Foods to limit or avoid

Certain foods increase your odds of developing kidney stones. Here are a few.

Salty and high-sodium foods

Higher salt consumption will bring higher sodium levels in urine to promote stone formation.

“American diets are terrible when it comes to salt intake, and it’s not just a matter of people adding table salt to foods,” reports Dr. De. “Many foods we buy at the store already contain a large amount of sodium.”

Sodium levels are often high in processed foods, including many you might not suspect. The list includes:

• Deli meats
• Salad dressings
• Cereal
• Bread
• Soups
• Pasta sauces
• Packaged snacks (like chips and pretzels)

Try to limit your sodium intake to 1,500 to 2,000 milligrams a day. To put that in perspective, that’s the amount found in about a half-teaspoon of salt.

Animal protein

Regularly loading your plate with animal protein — including beef, poultry, pork, and seafood — can kickstart kidney stone production. That’s because digesting animal proteins can trigger:

• Increased uric acid production
• Lower urine pH levels
• Increased calcium excretion

“These are all factors that increase your risk of kidney stones,” says Dr. Gutierrez-Aceves.

Now, this doesn’t mean you shouldn’t eat any meat. It’s more a matter of eating meat in moderation and paying attention to portion size. This means limiting meat consumption to no more than 3- to 4-ounce servings. (That’s roughly the size of a deck of cards.)

“You don’t need to become a vegetarian,” notes Dr. Gutierrez-Aceves, “but less meat is better if you’re looking to prevent kidney stones.”

High-oxalate foods

So, what exactly are “oxalates” and when do you eat them? Basically, oxalates are a natural compound found in many plant-based foods — including some “good-for-you” foods.

Too many oxalates in your system could lead to the formation of calcium-oxalate stones. In some cases, doctors may recommend a diet that limits oxalates to help prevent stones. That would mean watching your intake of foods such as:

• Spinach
• Beets
• Rhubarb
• Nuts (like almonds)
• Beans

Again, this doesn’t mean you can’t eat these items — but moderation is key, stresses Dr. De. So, if you’re prone to kidney stones, you might want to rethink eating a spinach salad with nuts every day for lunch.

Sugary foods and drinks

Got a sweet tooth? Well, you might want to tame that habit a bit if you’re worried about kidney stones. High sugar intake through sweets and treats can boost calcium concentration and reduce citrate levels in urine to fuel stone growth.

Kidney stone diet: A sample day of eating

If you take the advice above and put it into action, a day of eating might look a little something like this:

Breakfast

Oatmeal made with milk

Blueberries and a sprinkle of nuts

Coffee or tea

Midmorning snack

Greek yogurt

Orange slices

Water

Lunch

Grain bowl with quinoa, veggies and grilled chicken or tofu

Side salad (use greens other than spinach if you eat spinach often)

Sparkling water with lime

Afternoon snack

Apple and a cheese stick

Water

Dinner

Salmon, chicken or bean chili

Steamed carrots

Small baked potato with a spoonful of sour cream

Water with citrus

Lifestyle tips beyond diet

While diet can be a big part of kidney stone formation, it’s not the only factor. Other ways you can reduce kidney stone risk include:

• Maintaining a healthy weight: Obesity can alter your body’s metabolism and urine composition. This can increase the likelihood of kidney stones forming.
• Knowing your family history: Kidney stones often run in families. If that’s true for you, it’s extra important to take precautions to minimize your chances of getting a painful pebble.
• Talking with your doctor about supplements: Some supplements — like vitamin C, turmeric and calcium — may increase stone risk. Others, like fish oil or vitamin B6, may help reduce the risk. Review supplements with your provider before starting them.

If you consistently get kidney stones despite taking precautions, talk with your healthcare provider. They may be able to perform additional testing for more personalized dietary recommendations and prescribe medications to help prevent stone formation.

Final thoughts

Don’t feel like you have no control over kidney stones, encourage Dr. Gutierrez-Aceves and Dr. De. There are actions you can take — like following a kidney stone diet — that can limit your risk.

In other words, what you eat today may keep a kidney stone from forming tomorrow.