Taken like this, high carb looks better, doesn't it? Until we learn that the blood glucose measurement is done two hours after eating. If it was done immediately after eating, or even during the meal, not only would the numbers be reversed, it would look really bad for high carb.

When eating zero carb, or very little carb, blood glucose barely rises immediately after the meal. This is due to insulin's action on blood glucose combined with the lack of incoming carbohydrate, which in turn fails to make blood glucose rises. If anything, eating zero carb will cause blood glucose to drop during and after a meal. Some time after that, oh let's say two hours, hormones will kick in and slowly return blood glucose to normal range. That's quite different from what a high carb meal does, isn't it? We eat carbs, blood glucose rises above normal, insulin kicks in, and blood glucose slowly drops back down to normal range. But all this time before it happens, blood glucose was artificially (i.e. from the meal and not the body itself) maintained above normal range.

Two-hour-post-meal measurement is about as reliable as looking at somebody from ten feet away. It only gives us a glimpse of what's really going on. It doesn't tell us, for instance, how much and how long blood glucose stays above normal over the entire day. In other words, it doesn't tell us how big the area is under the curve.

There is a way to measure this curve. Test blood glucose as often as possible once the meal starts until two hours post meal. But that would be too simple. It would teach us too much about blood glucose.