There's the theory of insulin for Alzheimer's. Insulin is degraded by the insulin-degrading enzyme. Two organs have this enzyme, the liver and the brain. When there's excess insulin, from a high-carb diet for example, the liver can't keep up, the brain takes over. The enzyme also degrades amyloid, which is a potential culprit in Alzheimer's, it accumulates. The enzyme preferentially degrades insulin. So, the idea is that when there's excess insulin, (in the brain) the enzyme is too busy with that, it doesn't degrade amyloid (or less than it normally should), amyloid accumulates.

About the Ketoflex 12/3 diet. I did a quick search on Pubmed and duckduck, found nothing solid about it (compared to the Atkins diet for example, which has several solid experiment papers, like the A-TO-Z experiment by Chris Gardner). The bulk comes directly from the inventor, the rest comes from believers. In short, Ketoflex 12/3 is designed with the belief that it will work as is, without actually having been tested extensively beforehand. That's pretty much the same for almost all other diets on the planet. The point here is that if it looks like low-carb, it's because it is, but then there's several other low-carb diets (which we discuss daily on this and other forums) that have been tested extensively, which should likely serve at least as well as an untested diet.

It's the fiber thing. I see no basis to advise to eat fiber for any reason whatsoever, it's indigestible, it provides zero nutrition, and some forms of fiber bind to nutrients thereby making them unavalable to us. Atkins for example doesn't advise to eat fiber, it advises to eat non-starchy veggies. We could interpret this to mean it advises to eat fiber, but the advice is actually to avoid starchy veggies, because Atkins is a low-carb diet, not a high-fiber diet, see?

OK, go here ( https://www.ncbi.nlm.nih.gov ) that's PubMed a repository for all published scientific papers, search "alzheimer's ketogenic" without the quotes, start reading.

Well, it looks like he's really trying to help people, but it also looks like he's really trying to distinguish himself from the mob by positing a bunch of untested theories, especially about specific mechanisms and such. To me, this means his patients will serve as guinney pigs. So, whatever his method you wanna try, search beyond his website and papers to see if it's been done before by others and with success. I mean, if something truly works and has been tested extensively in several experiments with published papers and such, the underlying mechanisms don't need to be emphasized so much. All you'd need to say is "do this, it works, and by the way here are all the scientific papers published on it".