The Glycemic Index Explained
The glycemic index was created by nutritionists and researchers in the 1980s who were looking for a more accurate way to compare carbohydrates of different food groups relative to the conventional method of simply comparing the total number of carbs. If you want to know the basics of carbohydrate metabolism, that can be found here.
This index compares different carbohydrates and evaluates them based on how much they increase blood sugar after ingestion. The higher the glycemic index, the more it increases your blood sugar. Thus, the lower the glycemic index the better. There are three categories, high (>70), medium (56-69) and low (<55). The usefulness of this index is it allows easy comparison of different types of carbohydrates, including simple and complex.
There is strong evidence that suggests diets rich in foods with a high glycemic index is associated with increased risk of diabetes. Diets consisting of foods with a high glycemic index are also associated with increased triglycerides and insulin resistance. Individuals on a low glycemic index may have a reduced risk of developing diabetes. macular degeneration and coronary heart disease.
One limitation of the glycemic index is that it does not account for the amount of carbohydrates consumed, just the type. It’s utility in mixed meals and lack of long term studies are two other limiting factors in the utility of the glycemic index.
You may also hear about the glycemic load. The glycemic load adjusts for both quantity and quality whereas the glycemic index only adjusts for quality. While the usefulness to physicians and the population at large remains debated, you can still use it to guide your food choices when the information is available.
The rule is simple, the lower the glycemic index or glycemic load, the better. Below are some examples of high glycemic index foods and low glycemic index foods.