Foods such as citrus fruits, lean proteins, vegetables and whole grains prevent the formation of kidney stones. Adding these to the diet provides kidneys with the citrate they need to fight stones and keep uric acid levels low enough to prevent urate stones, as stated by the National Kidney Foundation.
One common treatment for chronic kidney stones is potassium citrate. Instead of (or in addition to) supplements, adding lemonade as well as oranges, grapefruits and other high-citrate foods to the diet also helps to prevent kidney stones. It is important to choose juices that are sugar free because the sugar in fruit juices can play havoc with blood glucose levels. The citrate may keep calcium in the urine from bonding with oxalate or other substances to make stones, and it may also keep existing crystals from growing, states the National Kidney Foundation.
Organ meats, fatty cuts of red meat, and shellfish are among the list of foods high in purines. These add a heavy dose of uric acid to the urine, and when the body cannot process all the acid, it turns into urate crystals -- and uric acid stones. Consuming more produce and whole grains and less animal protein keeps excess purines out of the system, making the raw materials for uric acid stones scarce, notes the National Kidney Foundation.