1. Red meat
The value in red meat is its protein content. Our bodies need protein to grow and build muscles, but it is challenging for kidneys to metabolize. Red meat is also quite high in saturated fat. Again, our kidneys need some fat to work properly, but too much can cause the formation of cells called macrophages in kidney tissue. That ultimately damages the kidneys and leads to a build-up of acidic residue in the body.
Red meat, especially organ meat, contains a high amount of something called purine, which stimulates the production of uric acid. The kidneys typically process out uric acid, but when you get too much purine, painful stones tend to develop.