This study has interesting graphs which show the variability of glucose fluctuations in those whose blood glucose is still in the "normal" range (as in, if you are waiting for a diagnosis as a warning, you might not get one till you are over the mark, but this can help you see if you are on the way there now.)
“It is interesting to note that although individuals respond differently to different foods, there are some foods that result in elevated glucose in the majority of adults. A standardized meal of cornflakes and milk caused glucose elevation in the prediabetic range (>140 mg/dl) in 80% of individuals in our study. It is plausible that these commonly eaten foods might be adverse for the health of the majority of adults in the world population.”
I wonder how many 50 year olds are metabolically healthy enough to eat corn flakes with milk and not see their blood glucose climb over 120 mg/dL (max healthy level) at peak. I bet it would be a quite small percentage.
If only there were some insulin tests we could undertake in order to bring attention to metabolic dysfunction long before it materialises as glucose dysregulation?
For the avoidance of doubt, that was sarcasm. I can't see regular NHS insulin testing becoming a thing in my lifetime. It would open pandora's box and reveal the vast swathes of the population that are dangerously ill and getting worse following the advice of their government.