The glycemic index can be used to help choose the foods you eat while on a diet. Some popular commercial diets use the glycemic index as a basis, but you can follow a glycemic index diet on your own as well. Diets using the glycemic index are usually fairly easy to follow and don't require extreme restrictions of foods or food groups.
Glycemic Index
The glycemic index assigns a number to every carbohydrate-containing food, indicating how high and how quickly 10 to 50 g of carbohydrates from that food raise blood sugar over the course of 2 hours in comparison to the rise in blood sugar caused by the same amount of a pure sugar solution during the same time frame. The scale ranges from zero to 100, with higher numbers causing a fast, high blood glucose response and lower numbers causing a more moderate response. When blood sugar spikes, the body responds by shuffling some of those extra sugars into storage as fat. The subsequent drop in blood sugar, after insulin clears it from your system, cause hunger and cravings that can lead to overeating.
GI and Weight Loss
The glycemic index can be used for weight loss because a diet full of foods with a high glycemic index tends to cause weight gain over time while a low glycemic diet tends to lead to weight loss. Low glycemic foods spend more time in the digestive tract, thereby delaying hunger. According to the Linus Pauling Institute, few long-term studies on using the glycemic index for weight loss exist, but in short-term studies, the use of a glycemic-index-based diet aids weight loss and may help prevent obesity.
Glycemic Load
One major drawback of the glycemic index system is that it does not look at serving size or how many carbohydrates occur in a single serving. While apples and table sugar may have similar glycemic index numbers, it would take about seven apples to consume the same amount of carbohydrates as only about 2 tsp. of sugar. The Glycemic load was created to address the problem of comparing foods with high amounts of carbohydrate to those with low carbohydrate levels. When the amount of carbohydrates in a single serving of apple is taken into account, the glycemic load is 6, a very low number.
Using GI and GL
The Glycemic Index Foundation recommends using GI and GL as general guidelines, not as a definitive guide to every food you eat. Instead of choosing only low glycemic foods, use the index to guide your choices when you have two or more options to choose from. Another use of the glycemic index for dieting is to use it to choose at least one low glycemic food to eat at every meal. Consuming low glycemic foods throughout the day helps modulate blood sugar so that the effects of the low glycemic food are felt at subsequent meals, even if those meals don't contain any low glycemic foods.
