Just three basic steps can help most stone formers prevent future stones. Making these changes can help reduce your chance of having another stone by at least 50%. As a bonus, these changes have other health benefits above and beyond preventing kidney stones. For example, staying well hydrated can also make your skin look healthier, improve your alertness, and help with weight loss.
Step one: Increase your regular water intake by one liter a day. This is equivalent to two tall glasses or two typical 500ml grocery store water bottles. (One liter = 4.2 8-oz glasses or 34 oz).
Why?: By increasing your fluid intake, you reduce the concentration of your urine, making it less likely for stones to form. In fact, in a randomized study of kidney stone patients, patients who drank enough additional water to make an additional liter of urine over patients who drank their normal amount of fluid were 50% less likely to form another stone in the next five years.
Step 2: Avoid too much salt in you diet. For the general healthy population, your total daily salt intake should be only 2300 mg a day, equivalent to a teaspoon of table salt.
Why?: A high sodium intake can increase the amount of calcium excreted in your urine and decrease urinary citrate, making it more likely that you will form another stone. In a clinical trial of kidney stone patients, those who were instructed to take a low salt and low protein intake were less likely to form another stone than those who were told to reduce their calcium intake.
Step 3: Eat more healthy foods such as fruits and vegetables and less meat. Most adults should eat only 5 to 6 oz of protein daily.
Why?: A high protein intake will increase your calcium, oxalate, and uric acid excretion in your urine. All of these things will make it more likely for you to form another stone.
Not sure how much food contains 2300 mg of salt or 6 oz of protein? We didn’t either at first. Our page on dietary prevention of stones can help. It contains food equivalences information that makes it easier to understand these amounts in terms of real world food. We also have a handout which summarizes this information: