What Should I Eat to Prevent Kidney Stones?
Quick answer: Stay heavily hydrated, reduce sodium and animal protein, and eat calcium-rich foods with meals. Most kidney stones are calcium oxalate — high sodium and low fluid intake are the main dietary causes.
What to Eat
Lots of water (2.5–3L daily)
The single most effective prevention — dilutes urine so crystals can't form.
Citrus fruits (lemons, oranges, limes)
Citrate in citrus inhibits calcium crystal formation — lemon water daily is clinically recommended.
Calcium-rich foods at meals (dairy, fortified foods)
Dietary calcium binds oxalate in the gut and prevents its absorption — reduces oxalate reaching kidneys.
Fruits and vegetables (most types)
Increase urine volume and provide potassium citrate which reduces stone risk.
Plant-based proteins (beans, lentils)
Lower acid load than animal protein — high animal protein raises urinary calcium and uric acid.
Magnesium-rich foods (nuts, seeds, whole grains)
Magnesium binds with oxalate in the gut, reducing oxalate absorption.
What to Avoid
High-sodium foods (processed foods, fast food, salty snacks)
Excess sodium causes the kidneys to excrete more calcium in urine — promoting stone formation.
Animal protein in large quantities (red meat, poultry, eggs)
Increases urinary calcium and uric acid — contribute to both calcium and uric acid stones.
High-oxalate foods (spinach, rhubarb, beet greens, nuts in excess)
Relevant mainly for those with calcium oxalate stones — pair with calcium foods rather than eliminating completely.
Sugary drinks and high-fructose corn syrup
Fructose increases urinary oxalate and uric acid excretion — raises stone risk.
Vitamin C supplements over 1000mg/day
Converts to oxalate in the body — can raise urinary oxalate levels in stone-formers.
Calcium supplements on an empty stomach
Supplements (not food) taken without food don't bind gut oxalate and may increase stone risk.
Hydration
Drink enough water so your urine is pale yellow — at minimum 2.5L daily. Lemonade (real lemon juice in water, unsweetened or low sugar) is specifically beneficial for calcium oxalate stones. Avoid sugary drinks.
Tips
- •The most important rule: more water. The volume of urine is the strongest protection against stone formation.
- •Don't restrict calcium from food — low calcium diet paradoxically increases oxalate absorption.
- •Do restrict sodium — this changes urinary chemistry more than almost any other dietary factor.
- •If you've had a stone, ask your doctor for a 24-hour urine analysis to identify your specific stone type and tailor advice.
- •Night-time stone risk is higher — drink water before bed and have water beside you overnight.