Several posts ago I mentioned a term without defining it. Then I realized I had learned it in medical school a long time back (1962-1966). When Dr. Dean Ornish talked about it in his book The Spectrum, I had to think long and hard about what glycemic index meant. In doing so I translated it in my mind from what I call "med-speak, i.e., terms we use as docs that mean little or nothing to most people, to regular-person language. And in doing so, I decided to change my diet a bit
I want to return to the term and what it actually means, because it's an important concept, even more so today than it was forty-plus years ago. We're talking here about what is termed "good carbs" and "bad carbs," with carbs, of course, being short for carbohydrates. Bad carbs are so-called simple carbohydrates like sugar, white flour and the ubiquitous high-fructose corn syrup (look at labels; it's everywhere); good carbs are complex carbohydrates with examples including the carbs in fruits and veggies and whole grains. Dr. Ornish points out that good carbs are unrefined and therefore high in fiber content.
So back to the glycemic index: it measures how quickly the carbs in whatever you eat turn into sugar in your blood; good carbs, since they come with built-in fiber, are foods that we break down and absorb more slowly, so your blood sugar doesn't go popping up. In a nation with more and more people being obese and many of those developing diabetes, your choice of what carbs you eat may be crucial to your health.
That's true for the rest of us because there's even another concept that comes into play and that one is "glycemic load"; that one takes in account how much total sugar gets into the bloodstream as compared to how rapidly it gets there. I eat carrots which have a high glycemic index, so whatever sugar they contain is absorbed rapidly, but not many grams of carbs per carrot, so I don't get a total sugar rush from them. I also eat Grape-Nuts, which have lots of carbs, so, even though they're not absorbed quite as quickly as my carrots, they give me a whole bunch of sugar for my body to handle.
If I were obese, it would partially because that sugar load and all its cousins got changed into fat. If I change to eating good carbs, I can help break this cycle. There's more science stuff involved, but that's enough for today