@Juliana.Rivers,
I don't have a copy of the book, as I got mine from the Public Library. But what I still remember was him saying something about how before he started his diet his fasting blood sugar was slightly elevated though not diabetic, then he reported his fasting glucose test value which was, in fact, fully diabetic--unless you were using the diagnostic criteria that were in use before they were revised, worldwide, in 1997.
This really surprised me because it would have taken half a minute to check this on Google. Elsewhere I believe there were other less glaring statements that made it clear that Dr. M is completely unaware of how blood sugar works or should be treated. Most importantly, while he said something mushy about how the diet might not be suitable for diabetics, he did not spell out WHY. In fact, it is only unsuitable for diabetics who are using a specific group of older oral drugs or injecting certain kinds of insulin because those drugs are dosed with the assumption that the person is eating a large amount of carbohydrate and without that carbohydrate they will hypo.
But anyone with diabetes using a whole other set of drugs approved after 1997 or who understands how to use the DAFNE insulin protocol (which has even spread to the UK a decade after it was used in the US) would be fine fasting.
OTOH, fasting alone is not the best dietary approach for people with diabetes. They really need to back off the carbs. So to suggest that the diet reversed his prediabetes (which was really diabetes) as his book does, again shows a lack of medical awareness.
My guess is that after a few years of maintaining with one fast a week, Dr. M's fasting blood sugar is very likely to rise again and over time his post meal numbers are likely to deteriorate, as that is what has happened to most people I've heard from who began to develop diabetes in the pattern he describes (fasting blood sugar elevated first) whether or not they lost weight. It's apparently a genetic thing. The appropriate dietary treatment is to cut down on carbs every day not just two days a week. This is more likely to preserve what insulin secreting ability the person still has.
Beyond that there were a few citations of the very few studies of non-intermittent fasting, on which the claims of its benefits were based, but non-intermittent fasting works quite differently from intermittent fasting. That's because a 4 day fast will completely drain glycogen and put people into a ketogenic state after day 2. Thus most of the benefits of that kind of fasting are the benefits you see from a strict low carb diet, but with 5:2 as he describes it you never get into a ketogenic state because it takes between 2 to 3 straight days of eating less than 100 g of carbs a day for that to happen.
And of course, what we are doing in 5:2 isn't even, technically, fasting, as we are eating, just not very much, on fast days. This, of course, is a benefit, not a problem with 5:2. Actual fasting often causes changes in thyroid function that we would all like to avoid (euthyroid syndrome, where T3 is present but not in its activated form, leading to exhaustion and slowed metabolism.)
The other thing I found annoying about the book was that it didn't go into any of the issues that arise when people attempt to fast, which are so well covered on this board. It really did seem like an opportunistic book written to cash in on the huge amounts of money available to anyone with an M.D. who comes up with a new Miracle Diet to be sold to the desperate people who have failed to lose weight on all the other miracle diets.
The advances for those kinds of books can be in the many hundreds of thousands of dollars and their earnings in the millions. So doctors are always coming up with new, and often fake twists with which to attempt to cash in. In this case, as I said before, the diet is a good one, though it is actually a tweak of the Johnson Up Day Down Day (JUDDD) diet which has been around for several more years and has been actively discussed all this time in another online diet board.
So to me this is another of those books that is written in a style that automatically would make any medical professional who knew anything about the topic completely discount it as hucksterism, just like the Atkins diet, which though it was an excellent diet was written up in such a hyperbolic, huckstery way that it took decades for it to get taken seriously. That approach while it makes money for the author makes it TOUGHER to get the concept into widespread use.
