My wife @lisaaase is a member of this group too so I'm tagging her. She had been diagnosed with Stage 3 Kidney Disease (which I understand is nothing near what @m1rmiller has) a few years ago and has been on a mostly grain-free, low-carb diet and mostly one meal a day (OMAD) intermittent fasting. Her most recent blood tests show normal kidney function. She's just one case, but in addition to other health benefits it seems her approach has helped with kidneys too.