Accessibility View Close toolbar

Factors That Influcence the GI Value of Food


The Glycemic Index - Part 2

By Dr. Keith E. Lewis
June 26, 2008

The following foods are commonly ingested by many people. Our patients oftentimes have questions about these different foods and how to make better choices about food selections.

Many of our patients like breakfast cereals and surprisingly enough not all breakfast cereals have a high glycemic index value; some, however, very high. For example, Kellogg's Corn Flakes has a GI value of 92, whereas Kellogg's All-Bran has a GI value of 30, which is considered low. Different grains and pastas also vary in terms of high glycemic values to low glycemic values.

In the past, when we thought about good carbs, bad carbs, and carbs in between carbs, we have always thought about pastas as being just definite no-no's. However, if pasta preparation is performed al dente, which is still a little bit stiff, the glycemic load or glycemic index is considerably lower. For example, spaghetti cooked al dente has a glycemic index of 38, which is considered to be low.

Several of the rices, for example, Uncle Ben's Instant Rice has a glycemic load of 87, which is very high. However, Uncle Ben's Converted white rice has a glycemic index of 39, which is considered low, so again making better choices is what it truly is all about.


There are other foods which vary and are sometimes somewhat surprising. Tortilla chips, for example, is a good snack food, or a snack food at least people like to partake in may not be a good snack food. It has a glycemic index of 63, whereas peanuts have a glycemic index of 14, so again peanuts are better choice than Tortilla chips.

Dried fruits, typically have a glycemic index in the higher ranges. For example, raisins glycemic index is 64, cherries glycemic index 22, oranges glycemic index 48.

Vegetables also vary in terms of their glycemic index. Carrots have a glycemic index of 47. Potatoes, a baked average-sized potato has a glycemic index of 85. However, a new potato has a glycemic index of 57.  Again, it is about choices.

Over the recent years, we have also discovered that combining salads with meals, especially high-glycemic index meals, actually helps one control blood glucose levels. The use of vinegar, lemon juice, or even lime juice in the form of salad dressing combined with a mixed meal has significant blood glucose lowering effects. This is primarily due and related to acidity, which we have spoken about in part 1 of this dissertation.

Because of organic acids such as lactic acid, propionic acid, they all have blood glucose lowering effect, but reduction varies with the type of acid. It should also be noted that making better choices in breads will help control blood sugar levels. Sour dough bread, for example, contains natural acids due to natural fermentation processes. They would include lactic acid and propionic acid. They also can reduce blood glucose levels making better choices of better food groups without being deprived is really the key.

If you have further questions concerning any of these factors that influence the glycemic index and how it affects blood sugar level, you should contact your healthcare provider.