I'm not sure we can equate low glycemic index foods with foods that suppress the insulin response. They might have a small insulin response in common, but their effect on blood sugar concentration is not at all the same.
I have no insight on the studio but that it's only logical "impairment" must mean the response was even less than the one expected if the same amount of glucose and no sweetener was ingested.
Otherwise it's misleading and not surprising at all.
Right, I think that's what they meant. And the result would be that your blood glucose level would spike much higher than if you had a normal insulin response. It's unclear what the health effects of that would be.
