Here’s another great article from Dr Peter Attia describing the various actions and functions of insulin. It describes so much of what we teach in our nutritional counseling visits. Our version doesn’t require a biochemistry or physics degree to understand though.
He uses the same example of insulin deficiency, Type I diabetes, and insulin excess, a insulinoma that I have used: without insulin one cannot store nutrients in cells and with an unregulated excess of insulin one only stores nutrients in cells.
Definitely worth the read and retread to try and understand it all.