If you've recently been told to follow a low-oxalate diet — whether by a urologist after a kidney stone, a naturopath for inflammation, or you're just researching on your own — this guide will give you everything you need to get started.
What Are Oxalates?
Oxalates (oxalic acid) are natural compounds found in many plants. They're part of a plant's defense system. Your body also produces oxalates as a metabolic byproduct.
In most people, dietary oxalates pass through the gut and are excreted. But in susceptible individuals, oxalates can bind with calcium in the kidneys to form calcium oxalate kidney stones — the most common type, accounting for about 80% of all kidney stones.
In most people, dietary oxalates pass through the gut and are excreted.
Who Should Follow a Low-Oxalate Diet?
- Recurrent kidney stone formers — especially calcium oxalate stones
- People with hyperoxaluria — elevated oxalate in urine
- Post-bariatric surgery patients — increased oxalate absorption
- Those with IBD (Crohn's/UC) — fat malabsorption increases oxalate absorption
- Anyone interested in reducing oxalate intake for general health
How Much Oxalate Is Too Much?
There's no universal standard, but most experts recommend these daily targets:
- Low-risk: Under 100 mg/day (general prevention)
- Moderate restriction: Under 50 mg/day (active stone formers)
- Strict restriction: Under 40 mg/day (hyperoxaluria, recurrent stones)
For context, a single cup of cooked spinach contains over 750 mg of oxalates — more than 7 days' worth at a strict limit.
more than 7 days' worth at a strict limit.
The Highest-Oxalate Foods to Watch
These are the foods responsible for the vast majority of dietary oxalate intake:
Very High Oxalate (300+ mg per serving)
- Spinach (raw or cooked)
- Rhubarb
- Beet greens
- Swiss chard
- Cocoa/chocolate
High Oxalate (100-300 mg per serving)
- Beets
- Sweet potatoes
- Almonds
- Chia seeds
- Black tea
- Soy products (tofu, soy milk)
Moderate Oxalate (25-100 mg per serving)
- Potatoes (white, with skin)
- Whole wheat bread
- Oatmeal
- Raspberries
- Navy beans
For detailed values on any food, browse our database of 2,400+ foods with data from multiple peer-reviewed sources.
The Safest Low-Oxalate Foods
These foods are all under 10 mg oxalate per serving:
- Proteins: All meat, poultry, fish, eggs (essentially zero oxalate)
- Dairy: Milk, cheese, yogurt (plus the calcium helps!)
- Vegetables: Broccoli, cauliflower, cabbage, bell peppers, cucumbers, iceberg lettuce
- Fruits: Bananas, blueberries, grapes, melons, apples (peeled)
- Grains: White rice, white bread, white pasta
5 Strategies That Actually Work
1. Pair High-Oxalate Foods with Calcium
Calcium binds oxalate in your gut, preventing absorption. Eat calcium-rich foods at the same meal as oxalate-containing foods. Research shows this can reduce urinary oxalate by up to 50%.
2. Cook Your Vegetables
Boiling vegetables can reduce oxalate content by 30-87%, depending on the food. The oxalate leaches into the cooking water. See our full cooking methods guide.
3. Stay Hydrated
Aim for 2.5-3 liters of fluid per day. Dilute urine means less concentrated oxalate, reducing the chance of crystal formation. Water is best, but lemonade (citrate) is also beneficial.
4. Don't Eliminate — Substitute
Instead of cutting foods entirely, swap high-oxalate options for lower-oxalate alternatives. Spinach -> kale (60% less oxalate). Almonds -> cashews (significantly less). Sweet potato -> white potato (much less). See our food swaps guide.
5. Track Your Intake
You can't manage what you don't measure. Tracking daily oxalate intake helps you learn which foods contribute the most and stay within your budget. Even a few days of tracking reveals surprising patterns.
Common Mistakes to Avoid
- Cutting calcium: Low calcium actually INCREASES kidney stone risk. The AUA recommends 1,000-1,200 mg calcium/day from food sources.
- Obsessing over every milligram: Perfection isn't the goal. Focus on avoiding the very-high-oxalate foods and you'll see the biggest impact.
- Ignoring hydration: Fluid intake is arguably more important than oxalate restriction for stone prevention.
- Going it alone: Work with a urologist or registered dietitian who understands oxalate management.
Your First Week: A Simple Plan
- Day 1-2: Just observe. Log everything you eat and check the oxalate content. You'll be surprised what's high and what's safe.
- Day 3-4: Make your first swaps. Replace the 1-2 highest-oxalate foods with lower alternatives.
- Day 5-7: Focus on calcium pairing. Add cheese, yogurt, or milk to meals that contain moderate oxalate foods.
By the end of week one, most people have reduced their oxalate intake by 40-60% with minimal lifestyle disruption.
Next Steps
- Browse the food database — Look up any food's oxalate content
- Cooking methods guide — Learn how cooking reduces oxalates
- Food swaps guide — Find lower-oxalate alternatives
- Restaurant guides — Eat out safely at chain restaurants