We don't think about our kidneys that much, but they filter all of the waste products out of our blood and turn them into pee. It's pretty important to keep this system working well, so we don't get infections or other diseases in our kidneys, our bladders or our urinary tracts. Like the rest of the organs in our body, our kidneys work best when fed a healthy diet of plants, and they can get stressed by diets heavy in meat and animal products.