Ringi and bulkbiker, you are both misunderstanding the intent of this thread, in part because of my poorly worded OP.
Apologies.
My friend and I both prefer to get all of our protein from animal sources. That is not the issue being discussed here.
What I'm trying to learn is how to get some protein from plant sources to reduce the work load on the kidneys.
Her kidneys are very damaged. She only has 25% kidney function left. While lab test results will bounce up and down from day to day, the damage is not reversible. The goal is to not cause further damage.
In stage 4 CKD it becomes necessary to monitor sodium and potassium intake. Her upper limit is now 1500 g daily for each. Can't remember what her upper limit is for phosphorus. These levels are monitored closely because the kidneys are having a really tough time keeping these levels where they need to be for the body. If those levels increase too much, that can make things worse for her very quickly.
If either of you can find evidence that getting 100% of protein from animal sources within the context of stage 4 kidney disease, please share it here.
The goal is to stop further damage to the kidneys so dialysis can be delayed as long as possible. Once dialysis is started, average survival rate is 5 years.
For the last 2 decades or so, some patients have been able to significantly delay dialysis for years by reducing the work load on the kidneys with a specific diet and protein supplements designed for CKD.
Protein from animal sources is not a problem for those of us who have healthy kidneys. I do not yet understand why it's a problem for those with CDK. That said, those who use the CKD diet and plant based protein supplements are able to delay dialysis. But the supplements are very expensive. Not everyone can afford them. That's the problem.