The Glycemic Index (G.I.) is a numerical system of measuring how fast a carbohydrate triggers a rise in circulating blood sugar—the higher the number, the greater the blood sugar response. So a low G.I. food will cause a small rise, while a high G.I. food will trigger a dramatic spike. A list of carbohydrates with their glycemic values is shown below.

Try to eat lower on the glycemic index.

There are two listings of the Glycemic Index here. The first is based on food categories subdivided into specific foods. The second list is ordered by the GI. This makes it easy to locate high or low GI foods.

Except as noted, each of the G.I. values shown below are based on the some 80 studies in the professional literature referenced in The G.I. Factor, which I discuss further in two other pages at this Web site, The Glycemic Index and The G.I. Factor.

For each of the listings thanks to Gary Cristofoli, I am now able to show the glycemic index for each food based on white bread = 100 or glucose = 100. But the fact that there two glycemic indexes is confusing.

What is an index? Well, in the sense that I'm using it here I mean this definition from the Encarta dictionary:

"Number expressing relationship: a scale, or a number on a scale, that expresses the price, value, or level of something in comparison to something else or to a previously established base number."

The key is the "previously established base number." The numbers are meaningful only in relation to this base number and don't relate to the number of calories, portion size, or anything else.

At first some scientists fed 50 grams of glucose to their test subjects. They saw that this amount of glucose raised their subjects' blood glucose to a certain level. They called that level 100, which became the base of the index. Then they tested their subjects with other foods. If, for example, one of those foods raised their test subjects' blood glucose level 70 percent as much on average as the glucose did, then they assigned an index of 70 to that food. And so on with other foods tested.

That would be simple. However, many scientists found that their subjects hated to take 50 grams of glucose. They knew from experience of testing foods that if they used white bread as the base number instead, it was about 70 on the glucose index. So they were able to make another index with white bread as the base, setting it as 100, and feeding their subjects 50 grams of carbohydrates from white bread instead. Then, as they tested more foods they related them to white bread.

Still later, when the relationship of glucose to white bread was firmly established, it didn't matter when the scientists preferred to use a glucose index even though they tested their subjects with white bread. So these two indexes came into general use.

Unfortunately, many of the lay publications of the glycemic index fail to specify which one of the indexes they are talking about. I can understand why, because of all the questions I get asking me to explain myself.

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