Unfortunately, there’s a very widespread tendency carrying over to huge numbers of topics where oversimplication is routinely employed, including by scientists or even the majority of scientists in a field, resulting in bad conclusions.
One can measure whole-body response to glucose challenges. It’s a meaningful measure particularly from the standpoint of a Type II diabetic or person with “metabolic syndrome” avoiding harmful blood glucose levels, but from the standpoint of many other conclusions, going simply from this is dreadfully misleading oversimplification.
Insulin sensitivity of muscle tissue and fat tissue is generally not the same.
Two individuals could have identical “insulin sensitivity” (by the oversimplification) but one has excellent insulin sensitivity in the muscles, while not taking up much glucose into fat.
Another has terrible insulin sensitivity in the muscles, but the fac cells suck up glucose like a Hoover.
Their “insulin sensitivity” (if oversimplifying and neglecting differences between the tissues) is identical but is each condition equally desirable?
So, if you don’t have a problem with dangerously high blood glucose, don’t assume that something that improves your “insulin sensitivity” (by a whole body measure must be good, or the other way around.