Some sectors of the keto-blogosphere restrict protein to maintain a ketogenic state for weight-loss or brain health. I suspect that their biggest problem is not generically PROTEIN as it is the SOURCE.
While on this Strong Medicine regimen of mine (which got sidetracked over the weekend because of a theatre evening and two days out-of-town, alas), my intake is approximately 120 g. of animal protein per day, at least half of which is beef or lamb. I allow myself fresh pork, fatty poultry or fish as the rest of the ration, but usually avoid eggs because they don't seem to satisfy me as well. My ketone readings get up into the moderate range.
And i'm highly-talented at gluconeogenesis. On a ZC or ULC diet, my morning glucose can read in the low-to-mid nineties. If anyone were to be able to screw up ketogenesis, it would be me.
Do people who complain of too much protein converting to glucose eat MORE than i do? 120 grams are almost TWO grams per ideal-weight-in-POUNDS for me -- that's a shitload of protein! Is their idea of restriction 80 or 90 grams? Or is it around the one-gram-per-kilo-ideal?
I've paid attention to Wooo's twitter-observations about how she feels after eating different meat-meals. After chicken she's far more likely to report brain-noise and malaise than after eating ribeye. She's inclined to think it might be factory-farm-polluted animals, but I think it's more likely to be: 1) seasonings on commercially-cooked birds; 2) preservatives in the brining solutions of conventional poultry; 3) an intrinsic inferiority of the chicken proteins themselves.
We know that different amino-acids have different physiological effects. I think a problem with poultry (especially chicken- and turkey-breast) might just be the quantities and proportions of various aminos.
...Just like I think that one of the problems with even heritage wheat is its overabundance of glutamic acid....
Think about it, and observe it in yourself: exactly what kinds of meat do you feel best eating? What kinds have less-than-ideal after-effects -- do you FEEL different after eating beef as compared to chicken? The habit of keeping a food-journal that includes state-of-wellbeing can be a very helpful practice, in teaching you DETAILS of how different foods make you feel.
We've been brainwashed to believe that variety in our diets is important -- well, it especially is, if we're eating things that aren't intrinsically nourishing to begin with! It's enlightening how little variety you need from a nutritional point of view, if your main foodstuffs are organ meats, pastured eggs, wild-caught fish, and fresh fatty meats. Theoretically we don't NEED red meat AND white meat -- our tendency toward mixing-it-up has more to do with the entertainment aspect of our food rather than essential nourishment in it.