I am sorry if I have sounded annoying. I just never heard of someone performing way better by drinking pure glucose at a high carb count compared to lower carb count from complex carbs. I certainly have failed my OGTT twice and it was pretty clear that there are issues.
But also: your body does not absorb anything else but glucose. If you eat complex carbs, they break down to glucose and are sent to the bloodstream. Blood flows around beta cells and they sense increase in BG, so they dump insulin.
I also never heard of pancreas just stopping to produce insulin with age. I tried to google something like that months ago and they always claim it is due to some misfortune like pancreatitis that it can happen. Pancreas won't fail unless something is attacking it.
But yes, I honestly were ok on low carb until I got hit with kidney stones, so got scared into dropping it.
Different people react differently to different carbs.
My theory is that it is to do with food intolerances, but of course I lack the resources to run comprehensive studies to investigate my theory.
However, in my case, I am mildly intolerant to cows’ milk, and get a far higher bg rise from cow yogurt than I do from the same carb/fat/protein portion of sheep or goats’ yog.
Likewise, I am most definitely gluten intolerant, and for a period of several days after ingesting gluten, my blood glucose levels are much more ‘reactive’ and extreme, both high and low, than they are without gluten.
There are a number of different theories around, including gut permeability affecting the autoimmune system, and gut flora affecting food digestion and absorption. Again, I lack access to resources to investigate comprehensively.
It was the Libre and close observation which allowed me to spot these ‘ideosyncracies’.
They were not identifiable by prick testing.
I suspect that there are many other people out there with similar intolerances affecting their health in various ways.