Stone patients can eat tofu because the oxalic acid content in tofu, especially in brine or plaster tofu, is very low. Moreover, foods that are further processed from tofu, such as dried tofu, do not have high oxalic acid content and can be eaten by stone patients. This is because soybeans are soaked and most of the purines are removed, and tofu contains a lot of water, which further dilutes the purines, while calcium-rich foods, on the contrary, help reduce the risk of stones because the calcium in the food binds to oxalic acid and prevents excess oxalic acid from entering the blood and urine. Patients with kidney stones need not worry that eating tofu will aggravate their condition. What needs to be noted is that kidney stone patients should drink more water, consume moderate amounts of high-quality protein such as eggs, meat and milk, and eat less salt as well as oxalic acid-rich foods such as spinach, asparagus, peanuts and soy flour. As for healthy people, there is even less need to worry about eating tofu or soy products to trigger kidney stones. Patients with other types of stones generally do not need to avoid eating either.