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The low glycemic index diet, sometimes referred to as the GI diet, is based on the glycemic index. This diet was developed by a Canadian professor and was later published in a number of successful diet books. The popular South Beach diet was partially based on this theory. According to this type of diet, eliminating foods with a high glycemic index and replacing them with low glycemic index food, a person can potentially lose weight and better control his blood glucose levels.
The glycemic index was created by David J. Jenkins in the early 1980s. Foods are assigned numbers based on how long it takes the average human body to break them down and convert them to glucose, which is the body's energy source. In a low glycemic index diet, foods that are broken down quickly typically raise a person's blood glucose levels, and they are assigned a higher number. On the other hand, foods that are broken down slowly usually keep the body's blood glucose levels even, with little or no spikes.
In the index used with the low glycemic index diet, pure glucose is given the highest rating of 100, and other foods are compared to this. To find out the value for a certain food, a test group of people eat a certain amount of the food, and the glucose levels in their blood are tested every few minutes. Based on these levels, the food is assigned its glycemic index value. Foods that raise the levels of glucose in the blood significantly are given higher numbers than foods that only raise blood glucose levels a little.
Generally, foods with a GI number of 55 or less are considered to be low GI foods, and foods with a GI number of 70 and above are considered to be high GI foods. Any food with a GI number in between is considered to be medium or moderate GI foods. Typically, food items such as white bread, potatoes, and processed sugars have a high glucose index number, and foods such as whole grains and vegetables have a low glucose index number.
The low glycemic index diet can help some people lose weight, and it is especially successful for diabetics. Many doctors believe that replacing high GI foods with low GI foods can possibly help keep diabetes under control. Some studies suggest that a low glycemic index diet can help reduce the levels of bad cholesterol as well as the risk of certain heart conditions.