Anyone who wants to ready Fung's 'New Paradigm' can do so for free here
https://thefastingmethod.com/new-paradigm-insulin-resistance-t2d/
It is simply a new discussion on the age old speculation of what goes wrong with the action of insulin when insulin resistance develops.
I have absolutely no problem with Fung presenting it as a theory, while discussing the short comings of the 'lock and key' analogy.
But it really shouldn't be presented as a fact, or anything more than a discussion point. No proof has been offered, as far as I am aware. If there is proof, I would be very interested to see it.
Additionally, while I don't have a problem with Fung presenting his theory on his blog and in his books, I am afraid that I do have a couple of problems with the way Jim has presented it in his posts.
My first concern is that
@Jim Lahey claims that T2s swim in glucotoxicity for decades before diagnosis with diabetes.
While I am happy to agree that this
can happen, the reality is different for many, many T2s. There is plenty of evidence, and some of it can be found on
www.bloodsugar.101 , to suggest that different people develop insulin resistance and eventually T2 at different rates, and that their body copes with the rising IR in different ways. Jason Fung himself discusses this elsewhere on his blog in some of his many posts on IR. Some T2s develop raised blood glucose in a matter of weeks or months, and sometimes going in steps of rising blood glucose levels, sometimes post prandial, and sometimes fasting blood glucose.
https://www.bloodsugar101.com/how-blood-sugar-control-works
My second concern is a development of my first. Jason Fung's paradigm is pretty clear that
where possible the body copes with insulin resistance and rising blood glucose levels (glucotoxity) in T2s by tucking the glucose into the cells as fat. Until the cells are full. Yes. Absolutely. But then, in the majority of T2s, the next step is to increase the fat holding capacity by either creating new fat cells, or by enlarging the fat cells that already exist. For those developing T2s, the blood glucose levels do not simply escalate to toxic levels.
This is why for most T2s, they get fatter before their blood glucose gets out of control, because the body uses its fat storage mechanism to prevent the blood glucose levels from rising too high - right up until it can't cope any more - and that is when the blood glucose levels start to spiral up into diabetes levels.
Yes, of course, there are a minority of T2s who don't/can't gain weight, and yes, they are in a very difficult situation in that they are less likely to be tested for T2 because they don't look like T2s, and because they do indeed have higher levels of glucose in their blood and lack the fat cells to get rid of it into storage. They deserve a voice, and just as good quality treatment as any other person with diabetes. But they are still a minority, and their experience should not be used to make sweeping statements about how it works for all T2s.
Very important not to make general statements, especially when Fung's own paradigm discusses this aspect in detail.