Non-diabetic who's interested in bio-feedback here. The GI graph is indeed dramatic[1].

Equally dramatic, in my experience, is the effect of exercise in modulating glucose spikes. It quickly became apparent that if I walked or worked out at the gym within 30mins of a meal, dGlucose/dt and subsequently max glucose would be dramatically reduced. Eventually, I got into the habit of planning exercise post high-GI meals as a way eliminate spikes.

It was an effective weightloss strategy for me as opposed to strictly a glucose regulation method and a positive experience as a whole as I got to develop an intuitive understanding of a physiological process I had only a theoretical understanding of before.

1. It would have been nice to see a labeled abscissa[2][x-axis].

2. https://en.wikipedia.org/wiki/Abscissa_and_ordinate