What is the Glycemic Index?
Glycemic index is a phrase that is important to people following the paleo diet for several reasons. The first key to understanding glycemic index is to understand the difference between the glycemic index and the glycemic load. The glycemic index is a measure of the quality of the carbohydrates you are consuming, while the glycemic load is a measure of a combination of the quality of carbohydrates along with the quanity of carbohydrates, which is represented by a single number.
With this being said, a more in-depth explanation of the glycemic index is that it is a ranking of the carbohydrates in foods, on a scale from 0 to 100, based on their effect on blood sugar levels after they are consumed. Foods that have a high GI level are quickly digested, and cause a spike in blood sugar and insulin levels. Foods that have a low GI number are generally absorbed and digested more slowly by the body, and produce rises in insulin and blood sugar that are more gradual compared to those foods with a high GI level. Diets that consist primarily of foods with a low glycemic index have been shown to have a variety of health benefits, including improved glucose levels in people with Type 1 and Type 2 diabetes and weight control, because food with a low GI number help extend the feeling of fullness after eating, thus controlling appetite and delaying hunger.
The glycemic index of various foods is found using a scientific methodology. In order to determine the GI of a food, a group of 10 or more people are given a certain food, and then a blood sample is taken to measure their blood sugar levels over a period of two hours. This system of measurement is used consistently to create an index of a range of foods and their GI.
The paleo diet encourages the consumption of foods with a low glycemic index. There is a database of foods with a measured GI number, but beef, chicken, fish, avocadoes, seeds, and most fruits and vegetables are not found within the database, because these foods, which are the staples of a paleo diet, contain either no carbohydrates or so little carbohydrates that they cannot be measured. That means that these foods will not have a sharp affect on your blood glucose levels when eaten, and this idea is considered to be an important benefit of the paleo diet. Below are a few common foods that are not allowed when on the paleo diet, and their GI number, all of which are considered to be high numbers:
White bread made with wheat flour-75
Boiled red potatoes- 89
Baked Russet potatoes- 94
Baked sweet potatoes-94