laramie

The thing to remember about the glycemic index is that it applies to meals rather than individual foods. A piece of bread with butter on it has a very different glycemic index than just a piece of bread. It's not like counting grams of fat or grams of carbohydrate, where you just take all the numbers and add them up.

That being the case, I think some of the things being written about glycemic index are nonsense. I haven't read the book you are quoting, but if it really tries to classify foods as "good" or "bad" based on their standalone glycemic index, I am deeply suspicious of the science. A plain potato may have a high glycemic index, but most people don't eat plain potatoes. Most people eat potatoes with butter or sour cream, and they eat them along with a full meal.

I think the lesson of the glycemic index is that Mom was right when she said to eat balanced meals. If you eat a bagel all by itself, it probably does make your insulin level spike. If you eat the same bagel along with a chunk of meat and one orange vegetable and one green vegetable and maybe a little butter, the glycemic index for the meal is low, and presumably your pancreas is happier.