QUOTE from Dr Fung (emphasis mine):
“How does hyperinsulinemia lead to insulin resistance?” Remember that insulin unlocks the gate that allows glucose to enter the cell. Under conditions of persistently and abnormally high insulin, glucose enters the cell far in excess of energy needs. There’s simply too much glucose going into the cell, so it overflows back out into the blood. From the outside, it appears that the glucose cannot enter the cell and that insulin is not doing its job so this is called ‘insulin resistance’. The cell appears resistant to the effect of insulin. It is an overflow phenomenon, not a gummed-up lock and key one.
Imagine the cell to be a subway car. Insulin opens the door and the passengers (glucose in the blood) march in a nice orderly manner into the empty subway car (cell). But what happens if there are too many passengers? Insulin opens the door but the passengers cannot enter the subway car and are left at the platform. If the subway door is gummed up and doesn’t open, then the result is the same. But the problem is actually that the subway car (cell) is already overflowing with passengers (glucose). Now the glucose outside the cell simply can’t get in and is left crowded on the platform.” 
NOTE (my commentary)
There’s simply too much glucose going into the cell, so it overflows back out into the blood.
It is an overflow phenomenon, not a gummed-up lock and key one.
What gets my attention?
Do I understand the need or problem?
Do I understand the potential solution?
Do I understand how to apply that strategy?
What questions do I have for the experts? What might be the answers?
Who needs to hear this?
What do I do next?
SOURCE – Footnotes:
 Chapter Three: What causes Type 2 diabetes? – Dr Jason Fung, in Diabetes Unpacked: Just Science and Sense. No Sugar Coating by Tim Noakes, Jason Fung, et. al. Kindle location 949.
Photo by Diabetes Care, Insulin, via Flickr
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Key: Fung-10-30.34 Last Revision: 05/04/2021.