I'm not sure what the stats are, but my anecdote is that two family members who did long term keto have both developed permanent renal problems in their 60s. They can now eat only very little protein.
The one person's Dr. told her that the main issue is that she was eating way too much protein. Which might mean she wasn't doing Keto quite right. But I don't know enough about the diet myself to say for sure.
My guess would be this is just nonsense.
No one has an eating too much protein problem. The average person has a sitting on their ass problem that leads to all kinds of health issues, especially when combined with a too many calorie problem.
There is absolutely no evidence that long term high protein consumption leads to these things.
Thanks, that's very interesting.
I was concerned about that and had my liver checked a couple of years ago but it might have been too early then. I'll brush up on that.