The glycemic index (GI) is the measure of how fast a food can raise your blood sugar.
The Glycemic Index of Foods
High-GI foods: These foods have a GI of 70-100 and can raise your blood sugar very fast. For instance, pure sugar water is often classified at 100. Other examples include white potatoes, refined (white) breads, refined (white) grains, candy, watermelon, dried dates, and many more.
Moderate-GI foods: These foods have a GI 50-69 and can raise your blood sugar moderately fast. Examples are sweet potatoes, brown and white rice, beets, carrots, pasta, bananas, mangoes, and raisins.
Low-GI foods: These foods have a GI 20-49 and a low glycemic impact on your blood sugar. Examples are non-starchy vegetables, beans and legumes, whole grains such as wild rice, wheat tortilla, wheat pasta, barley, rye, bulgur, nuts, olives and oils, berries, and apples.
Starch vs. Resistant Starch
Starches are found in carbohydrate-rich foods, and raise your blood sugar. For example, we find starch in bread, cereals, pasta, corn, peas, potatoes, yams, and squashes. Please note these foods are part of a healthful diet. A resistant starch is a portion of the starch that resists digestion. This means we cannot digest it or absorb calories from it. Although we cannot digest it, only our gut bacteria can metabolize it. There are several types of resistant starches; you can think of them as fiber. Fiber benefits our good bacteria and, hence, your overall health.
How to Turn White Potatoes into a Resistant Starch
So, there is a simple way to transform an Irish potato into a resistant starch, meaning increasing the amount of fiber in the Potato. COOK (boil or steam) the potatoes, COOL or freeze them, then REHEAT them (Patterson, et al., 2019). The amount of fiber in the potatoes will increase since some of the starch crystallizes into a form that can no longer be digested. This simple cooking process gives you a nearly 40 percent lower glycemic impact from potatoes (Patterson, et al., 2019). This method benefits individuals managing diabetes, seeking to lose weight, or anyone trying to increase fiber and improve gut health.
References
Patterson, M. A., Fong, J. N., Maiya, M., Kung, S., Sarkissian, A., Nashef, N., & Wang, W. (2019). Chilled Potatoes Decrease Postprandial Glucose, Insulin, and Glucose-dependent Insulinotropic Peptide Compared to Boiled Potatoes in Females with Elevated Fasting Glucose and Insulin. Nutrients, 11(9), 2066. https://doi.org/10.3390/nu11092066