Many diet plans, including the glycemic index diet, focus on the dietary effects of carbohydrates. For most people, carbohydrates provide the majority of the calories in the diet, and carbohydrate intake has a powerful effect on blood glucose levels. Diabetics often follow the glycemic index diet, but anyone can use it.
Glycemic Index Determination
The glycemic index is a measurement as to how a food affects your blood glucose levels. The glycemic index of a food is determined by giving a volunteer a set amount of the food and then monitoring the volunteer's blood glucose levels over time. The resulting changes in blood glucose levels are then compared to the effects of a "control" food, such as white bread; the higher the changes in blood glucose levels after eating the test food, the higher the glycemic index for the food will be.
High and Low Glycemic Index Foods
The glycemic index diet encourages you to emphasize foods with low glycemic indexes. Low glycemic index foods have a value under 55 and include sweet potatoes, bread made with pumpernickel or stone-ground, whole-wheat, steel cut oatmeal, pasta, barley, corn, carrots and most fruits. High glycemic index foods have values over 70 and include short-grain white rice, melons, white bread, cornflakes and Russet potatoes; these foods should be avoided.
Benefits
Following a low glycemic index diet can help prevent sudden spikes in your blood glucose levels. This can help lower your risk of developing Type 2 diabetes, because jumps in blood glucose levels can cause you to become resistant to insulin. The glycemic index diet can also help you control your blood glucose levels if you have diabetes and may also lower your risk of developing heart disease and obesity.
Limitations
One of the limitations of the glycemic index diet is that glycemic index measurements are made on foods consumed individually, whereas you probably eat combinations of foods during a meal. For example, eating white bread along with protein or fat will reduce the increase in blood glucose levels. The glycemic index diet also doesn't consider the other nutrients in food, MayoClinic.com notes; foods with a low glycemic index may be high in fat or provide little in the way of nutrition.
