That was a generalized statement. There are a variety of confounding factors which can obscure what is going on. For example, was this while you were on or off of the diabetic medication/s?
I have never taken diabetic medications. But after years of trying to control my blood glucose with diet and exercise, my blood sugar spiked over a period of six months and my doctor was about to prescribe medication. That’s when I decided to go on a diet (I have always exercised so that was not an issue).