I’m sorry, but all I could think of is that digestion doesn’t happen in the kidneys or liver. It happens in the intestines. The filtering of the blood that the kidneys do is a passive process so unless there are toxins in the food, it doesn’t matter to a healthy kidney. I believe it’s close enough to the same thing for the liver. The problems arise when the kidneys or liver have been damaged or when there are toxins in the food, then the diet has to be altered to decrease the workload, to support the damaged organ, and stop further damage.