Key Takeaways
- A low-oxalate diet limits foods high in oxalate to reduce urinary oxalate and kidney stone risk
- The general daily target is under 100 mg of oxalate per day (some clinicians recommend under 50 mg)
- Pairing calcium-rich foods with meals – not supplements between meals – is equally important
- The diet works best alongside good hydration: aim for 2.5+ liters of urine output daily
- This guide is especially relevant for people with hyperoxaluria, recurrent calcium oxalate kidney stones, or related GI conditions
👉 Patient resources, specialist support, and clinical guidance at ohf.org
What Is a Low-Oxalate Diet?
A low-oxalate diet is a structured eating plan that limits foods containing high amounts of oxalic acid – a naturally occurring compound found in many plant-based foods. The goal is to reduce the amount of oxalate your body absorbs and ultimately excretes through the kidneys in urine.
When urinary oxalate is too high (a condition called hyperoxaluria), it binds with calcium in the kidneys to form calcium oxalate crystals – the foundation of the most common type of kidney stone. Reducing dietary oxalate is one of the most direct ways to lower that risk.
Quick Answer: A low-oxalate diet means eating less than 100 mg of oxalate per day by avoiding or limiting high-oxalate foods like spinach, nuts, chocolate, and beets – while eating enough calcium with meals to block oxalate absorption.
This isn’t just a kidney stone diet. People with primary hyperoxaluria, enteric hyperoxaluria (linked to Crohn’s, bariatric surgery, or IBD), and those at elevated stone risk all benefit from understanding and following this approach.
Who Should Follow a Low-Oxalate Diet?
A low-oxalate diet may be recommended for:
- People with elevated urinary oxalate (hyperoxaluria)
- Individuals with recurrent calcium oxalate kidney stones
- People with dietary hyperoxaluria related to high oxalate intake
- People with enteric hyperoxaluria associated with Crohn’s disease, inflammatory bowel disease (IBD), chronic pancreatitis, short bowel syndrome, or bariatric surgery
- Individuals with consistently elevated urinary oxalate on 24-hour urine testing
A 24-hour urine test is often the best way to determine whether elevated urinary oxalate may be contributing to kidney stone risk.
People living with Primary Hyperoxaluria (PH) may also receive individualized dietary recommendations from their healthcare team. However, because PH is a genetic condition that causes the liver to produce excess oxalate, dietary changes alone do not address the underlying cause of the disease.
Daily Oxalate Limits: What the Numbers Mean
Oxalate content in food is measured in milligrams (mg). A standard low-oxalate diet typically aims to stay under 100 mg of oxalate per day. For people with significantly elevated urinary oxalate, some healthcare providers may recommend a more restrictive target, often under 50 mg per day.
| Oxalate Level | Daily Target | Typical Use |
| Moderate Restriction | Under 100 mg/day | General calcium oxalate stone prevention |
| Strict Restriction | Under 50 mg/day | Individuals with elevated urinary oxalate under medical supervision |
The appropriate level of oxalate restriction should be determined with your healthcare team based on your diagnosis, urinary oxalate levels, kidney stone history, and overall nutritional needs.
To put this in perspective, a single cup of cooked spinach contains approximately 750 mg of oxalate-more than a week’s worth for someone following a strict low-oxalate diet. By comparison, a cup of cooked white rice contains about 4 mg.
How Sodium Influences Oxalate
Reducing sodium (salt) is another important part of kidney stone prevention. High sodium intake increases the amount of calcium released into the urine, which may increase the risk of calcium oxalate stone formation.
Simple ways to reduce sodium include:
- Limiting processed and packaged foods
- Choosing lower-sodium soups, sauces, and snacks
- Reading nutrition labels carefully
- Cooking more meals at home
For many stone formers, reducing sodium can be just as important as reducing dietary oxalate.
Low-oxalate diet: what to eat and what to avoid
A low-oxalate diet limits foods that contain oxalate, a naturally occurring compound that can bind with calcium in the body and contribute to kidney stones or oxalate-related conditions like hyperoxaluria.
Dietitians generally classify foods into three tiers: low-oxalate (under 10 mg per serving), moderate-oxalate (10–50 mg per serving), and high-oxalate (50 mg or more per serving). Safe, everyday protein choices include chicken, turkey, beef, fish, eggs, most cheeses, plain yogurt, and milk.
Low-oxalate vegetables include cauliflower, mushrooms, zucchini, green beans, cucumber, iceberg lettuce, and onions, while safe fruits include apples, bananas, cherries, grapes, melons, peaches, and mangoes. White rice, white pasta, white bread, and cornflakes are preferred grain options.
Water is the best beverage; diluted lemon water, many herbal teas, and dairy drinks are also well-tolerated. Foods to limit (moderate oxalate) include brown rice, whole wheat bread, strawberries, raspberries, asparagus, and small amounts of peanut butter.
The highest-oxalate foods to avoid or strictly minimize include spinach, beet greens, rhubarb, Swiss chard, almonds, dark chocolate, and black tea – many of which exceed 100 mg of oxalate per serving.
Oxalate values vary by preparation method and food testing source; always consult a registered dietitian or nephrologist before making significant dietary changes.
| Food (serving size) | Approx. oxalate | Tier |
| Beet greens, cooked (1 cup) | ~915 mg | High |
| Rhubarb, cooked (½ cup) | ~860 mg | High |
| Spinach, cooked (1 cup) | ~750 mg | High |
| Swiss chard, cooked (½ cup) | ~660 mg | High |
| Almonds (1 oz / ~23 nuts) | ~122 mg | High |
| Baked potato with skin (1 medium) | ~97 mg | High |
| Dark chocolate (1 oz) | ~55 mg | High |
| Peanuts (1 oz) | ~35 mg | Moderate |
| Sweet potato, baked (1 medium) | ~28–40 mg | Moderate |
| Peanut butter (2 tbsp) | ~13 mg | Moderate |
| Strawberries (½ cup) | ~15 mg | Moderate |
| Raspberries (½ cup) | ~14 mg | Moderate |
| Black tea (8 oz brewed) | ~14–75 mg | Moderate |
| Asparagus (½ cup cooked) | ~16 mg | Moderate |
| Brown rice (1 cup cooked) | ~13 mg | Moderate |
| Chicken / turkey / beef / fish | ~0–2 mg | Low |
| Eggs (1 large) | ~0 mg | Low |
| Cheddar / mozzarella cheese | ~0–2 mg | Low |
| Plain yogurt (1 cup) | ~0–2 mg | Low |
| Cauliflower (½ cup) | ~2 mg | Low |
| Cucumber (½ cup) | ~1 mg | Low |
| Mushrooms (½ cup) | ~1 mg | Low |
| Apple (1 medium) | ~3 mg | Low |
| Banana (1 medium) | ~2 mg | Low |
| White rice (1 cup cooked) | ~4 mg | Low |
| Oats, cooked (1 cup) | ~2 mg | Low |
| Water / lemon water | ~0 mg | Low |
When Diet Isn’t Enough For Hyperoxaluria
It is important to understand that not all hyperoxaluria is the same.
For many people with dietary hyperoxaluria or enteric hyperoxaluria, dietary changes, calcium with meals, hydration, and management of the underlying gastrointestinal condition can help reduce urinary oxalate levels and lower kidney stone risk.
For people with Primary Hyperoxaluria (PH), the body produces excess oxalate in the liver due to a genetic condition. While healthy eating and hydration remain important, diet alone cannot correct the underlying disease. Many people with PH require specialized medical treatment and ongoing care from experienced healthcare professionals.
Medical management may include:
- Pyridoxine (Vitamin B6) for some individuals with PH1
- Lumasiran (Oxlumo®)
- Nedosiran (Rivfloza®)
- Intensive dialysis in advanced disease
- Liver and/or kidney transplantation in select cases
Sample 3-Day Low-Oxalate Meal Plan
This plan targets under 100 mg of oxalate per day while meeting calcium needs through food.
Day 1
Breakfast: Scrambled eggs with mushrooms and diced zucchini, glass of milk, banana
Lunch: Grilled chicken breast, white rice, green beans, low-fat yogurt
Dinner: Baked salmon, roasted cauliflower and broccoli, white dinner roll, water with lemon
Snack: Apple slices, small cube of cheddar cheese
Day 2
Breakfast: Oatmeal (1/2 cup dry) with sliced banana, milk, and a drizzle of honey
Lunch: Turkey and romaine lettuce wrap in a white flour tortilla, cucumber slices, glass of milk
Dinner: Ground beef taco bowl with white rice, iceberg lettuce, shredded cheese, sour cream
Snack: Peach, glass of milk or yogurt
Day 3
Breakfast: Cornflakes with milk, boiled egg, orange juice (calcium-fortified)
Lunch: Tuna salad (canned tuna, mayo, celery) on white bread, pear
Dinner: Roasted chicken thighs, mashed potatoes (made with butter and milk, no skin), steamed peas
Snack: Grapes, mozzarella string cheese
Each day in this plan stays well under 100 mg of oxalate while naturally incorporating calcium at every meal. These are simple, accessible meals – not specialty ingredients or complicated cooking.
Not Sure Why Your Oxalate Is High?
Understanding the cause of elevated urinary oxalate is important because treatment approaches differ.
While dietary changes can be highly effective for some people, others may have an underlying condition such as dietary hyperoxaluria, enteric hyperoxaluria, Primary Hyperoxaluria (PH), inflammatory bowel disease, or a history of bariatric surgery that requires specialized evaluation and care.
The Oxalosis & Hyperoxaluria Foundation (OHF) provides educational resources, expert care information, research updates, and patient support for individuals and families affected by all forms of hyperoxaluria.
Whether you’re newly diagnosed, searching for answers after recurrent kidney stones, or caring for a loved one with hyperoxaluria, OHF can help connect you with trusted information and expert resources.
Frequently Asked Questions
Q: How quickly does a low-oxalate diet reduce kidney stone risk?
Urinary oxalate can drop within days of dietary changes. However, meaningful reduction in stone formation or growth typically takes months. Consistent adherence over the long term is what drives real outcomes.
Q: Can I ever eat spinach again?
Small amounts of spinach are less of a concern if your overall daily oxalate is well within your target. Most dietitians recommend occasional small portions rather than complete elimination, unless you’re on a strict medical protocol.
Q: Is a low-oxalate diet the same as a low-carb or keto diet?
No. They can overlap somewhat (meat and eggs are low-oxalate), but keto diets often include almonds, nut flours, and dark chocolate – all high in oxalate. Always evaluate any diet plan against an oxalate food list before starting.
Q: Do I need to follow this diet forever?
For most people with dietary hyperoxaluria, long-term dietary modification is recommended to prevent recurrence. However, the specific level of restriction should be guided by ongoing urine testing, not assumed.
Q: What’s the best app or resource to track oxalate intake?
Several dietitian-developed oxalate food databases exist online. The Oxalosis and Hyperoxaluria Foundation (ohf.org) provides clinically reviewed resources to help you navigate food choices accurately.
This article is for informational purposes only. Always consult a nephrologist, urologist, or registered dietitian before making significant dietary changes, especially if you have a diagnosed kidney or metabolic condition.
