HI lived with stage 4 kidney disease for 10 years on dialysis. Diet is a tricky thing with renal failure and most of the renal diet is totally in opposition to keto style eating. Recommended foods are white bread and white flour products, white rice, low protein, lower fat intake. Low protein is required because your kidneys have to process excess protein which turns into BUN (Blood Urea Nitrogen) which has to be removed by dialysis. Totally limiting any high potassium or high phosphorus foods as much as possible i.e. not too much meat, very limited dairy(double whammy there!) avocado, tomatoes, bran from whole grains, you get the idea.
When the kidneys are not working up to capacity phosphorus and potassium can build up in the blood and cause bone deterioration, organ calcification, and cardiovascular risk (they use potassium for lethal injection executions) and a myriad of other issues. Water intake is also limited to 500 ml. In many cases where there is no longer urinating. So at stage 4 already too late for keto IMHO. I was lucky to get a transplant 12/2017 and started keto with two doctors approval to try and thwart post transplant pre-diabetes that I was starting to get from being on prednisone for life. If he’s still has kidney function it may be possible, or it might just be a strain that puts him over the edge into dialysis. Personally I would seek out a keto friendly doctor for advice.
