If your doctor has advised you to restrict your protein intake, as is the case in later stages of kidney disease, that is a problem for your long term health- why? It puts you at a 100% risk of sarcopenia, cachexia and muscle loss. This makes intuitive sense- because, if you are not taking it adequate amounts of protein anymore, where can your body get it? Right! From your muscles- leading to you losing muscle mass. This is already a problem in the aging population, but restricting protein to under 0.6g/kg or lower, like nephrologists need to do in later cases will make this a lot worse.

Incidentally having too little protein available will lead to a decrease in kidney function in and of itself. We are told to limit protein because of its nitrogen content- and it is true that this, similar to phosphorous, will over time decrease kidney function even more. So what is the solution? How can we prevent muscle loss and, even better, prevent further decline in GFR while still limiting protein? Many centers have trialed supplementation with KA/EAA (Ketoacid Analogs of Essential Amino Acids) – these give the body the building blocks it needs to maintain muscle mass while being nitrogen-free. In human trials, these have shown to stabilize loss of kidney function, improve body composition and stabilize inflammation.

They wont cure kidney disease, but they will stabilize it. Just limiting protein on the other hand does not stabilize it as much. Much more important though: YOU dont want to be in the position of having difficulty getting up out of your chair one day just because you had to restrict protein. I’m normally no fan of pharmaceuticals. In this case it might just be the best option to supplement with these amino acids- your body needs them, badly. Oh, and- yes, I did check how naturally occuring essential amino acids stack up. It depends on your function. If you are still doing reasonably well, try them. If your gfr stays consistent, your body can use the extra amino acids to keep it that way for longer and you can spare the expense of getting the KA-EAAs.

They do however not have the low nitrogen content that the KA versions have. If you are severely restricted in protein, they might not be a good choice. This makes it all the more apparent, that it is most important you make use of the little protein that you are allowed to eat and make it a very bioavailable one, getting many essential amino acids in the process. Grass-fed beef, Whey, even eggwhites if you are limiting phosphorous. And maybe include EAAs as part of your allowed protein, so that it does not come on top. Say, eat 20g of beef protein and 10g of EAAs.

This will of course not help to keep your muscle mass a lot, so please do get your doctor to prescribe KA-EAAs to you. A dosage of 1 tablet of “Ketosteril” per 5kg of body weight was used in one study.

An over the counter alternative is this product:
https://www.ketorena.com
More reading:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6312769/
https://www.ncbi.nlm.nih.gov/pubmed/29948444
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770434/