This discussion is very intriguing - looks like what the researchers are finding supports some of the anecdotal reports...
I went to Ben Lynch's SHEI conference last year, where Alessandro Ferretti spoke about ketogenic diets and there was a lot of dialogue between the many doctors in attendance on the nuances of ketogenic diets.
Best of all, they fed us ketogenic meals for entire event!! And Ferretti's photos of ketogenic meals were quite helpful... basically a variety of non starchy vegetables, happy animal protein and oil on the side. Pretty simple. They also pointed out that casein in dairy blocks methylation, so dairy products may be counterproductive for us.
I'm now implementing it finally, on my doctor's instruction, and it is helping with my brain fog.
Based on Fluge and Mella's findings and my own lab results, getting a good amount of protein is critical... I weigh 150 and 90-95g a day seems to be the right amount.
I'm also using C8 oil, NOT MCT or coconut oil, as well as flax seed, avocado, olive, and walnut oil. I'm finding I'm not as hungry for big meals, but when I eat, it's organic vegetables and happy fish, meat, or eggs with the fats.
Also, to help with ketosis, I started using keto esters, and found that putting them in water, along with Seeking Health creatine, d-ribose, and BCAAs, and drinking it before and during my limited exercise, that I didn't collapse as easily and PEM was reduced, and I was thinking more clearly.
Obviously, we're all different, but as some if the other posters have mentioned, if it's not helping, there may be individual pathway issues. My experience has been that if you unblock something, then you find the next bottleneck...
I've also been following work with ketogenic diets in the cancer world, and seems like this is an exciting area....no concrete answers, but promising developments for all of us...