The kidneys are vital organs, flushing out toxins from the body. They play a vital role to keep the body healthy and clean. If something is wrong with them, the rest of the body suffers, too. While there are many conditions that could affect the normal functioning of kidneys, there is no single eating plan that is right for everyone with kidney disease. What you can or cannot eat will change over time, depending on how much kidney function you have and other things, like having diabetes, cancer etc.