The glycemic index was developed to categorize certain foods based on how quickly their carbohydrate portions are broken down within the body. These foods measured are made of carbohydrates which are broken down into sugars. A food which is broken down quickly into sugars has a high glycemic index. Conversely, foods which break down slowly have a low glycemic index. The purpose of the glycemic index was to help identify foods which were better to eat for those who have diabetes.
With a lower glycemic index, this indicates a slower rate of digestion as wells as the absorption of the carbohydrate. This may lead to decreased insulin levels compared to a high glycemic index, therefore, lower long-term glucose levels as well as cholesterol levels may be achieved.
To measure the glycemic index, a tested food is compared with a standard such as white bread. A set amount is given of the carbohydrate such as 50 grams. The standard food must have an equal amount of carbohydrate as the tested food.
Examples of high glycemic index foods are corn flakes, watermelon, baked potatoes, and white bread. The following are examples of medium-type glycemic index foods: basmati rice, sweet potatoes, and wheat bread. Low glycemic index foods consist of most fruits and vegetables, eggs, fish, brown rice, meat, nuts, and cheeses.
Studies have reported that lower glycemic index foods can significantly provide long-term advantages to decreasing the development of diabetes and heart disease such as coronary heart disease. A high glycemic spike occurs after a meal with a high glycemic index. The sequelae to this is a high insulin level and an oxidative stress to the vasculature which causes injury to the blood vessels. Hence, diabetes and coronary artery disease can arise. A university study in Australia noted that these diseases as well as cancer could develop over time with a high glycemic index diet.
One other study done showed a correlation between obesity and a high glycemic index diet. This study used male rats which were divided into two groups where one ate a low glycemic index diet. The other had a high glycemic index diet, and both were studied for 20 weeks. The group which had the high glycemic index had results showing an increased body fat content as well as a decreased lean mass content. Their bloodwork showed significantly increased triglyceride levels and insulin levels postprandial.
Therefore, this may be an important guideline to use in the evaluation of a healthy diet. It provides a use for those currently diagnosed with diabetes to maintain a proper glucose level. It also serves good purpose in the prevention of diseases like diabetes and heart disease.
The benefit to a low glycemic index diet is that glucose or sugars are broken down very slowly, and this prevents high levels of insulin in the body right after a meal. This increase in insulin may lead to diseases like diabetes which can have difficult complications such as amputations, loss of kidney function, or loss of eyesight. Other diseases can be prevented like vascular disease which would improve the health of your heart and blood vessels throughout the body.