Also, animal foods are low oxalate, while plants foods might be high. I put myself and DH on a low oxalate diet, (from the book Toxic Superfoods) and raised his "good" kidney number 22 points.

Dana Carpender, low carb author, set up a low carb diet for a friend of hers who was a kidney patient. She kept to his doctor's recommends for his level of protein, and his function improved. I think that's the only real restriction one should worry about.

The rest is literally manufactured food marketing. Which is blanketing the Earth. Nestle sends boats of junk food up the Amazon to rip off the Indigenous peoples who at least didn't have that problem before.