Some foods containing carbohydrates raise blood sugar levels faster and more drastically than others. This is especially problematic for people with diabetes, but it can also cause problems for others as well, since a rise in blood sugar is usually followed by a rise in insulin. High levels of insulin are linked with a number of serious health conditions, including heart disease, cancer and obesity, according to the Thagard Student Health Center at Florida State University. The gylcemic index is a tool that can help people to choose better food options to limit sharp spikes in glucose and insulin levels.
Identification
The glycemic index was created by determining how different foods containing carbohydrates affected blood glucose levels compared to a control food, such as white bread or pure glucose, according to the Linus Pauling Institute. Those that rank high on the glycemic index cause faster and sharper rises in blood glucose levels than those that rank low on the glycemic index.
Significance
The glycemic index is sometimes used by people who would like to lower their risk for type 2 diabetes, gallbladder disease, cancer, hypoglycemia, obesity, heart disease and polycystic ovary syndrome, as well as athletes before competitions. Diabetics also use the glycemic index to help track and control their blood sugar.
Considerations
A number of factors affect the glycemic index of food, including how processed it is, how it is cooked, how long it was stored, how ripe the food is and the variety or type of the food, according to the American Diabetes Association. This means a food, such as rice, can have a wide range of GI values, and GI charts cannot contain all of these values.
The GI value of a food changes depending on what it is served with, so eating a high GI food with lower GI foods can prevent you from having a large rise in blood glucose.
Significance
Although the GI value of a food can be helpful, you also need to keep in mind that foods with a high GI value that don't contain a lot of carbohydrate won't actually raise your blood glucose much, says the Thagard Student Health Center. The glycemic load of the food is a better indicator, as this takes into account both the glycemic index of the food and the amount of carbohydrate contained in the food.
You can't rely solely on the glycemic index to decide what to eat, as some unhealthy snacks have lower GI values than much healthier foods. You need to focus on the overall nutrition of the food, and the calories it contains, as well as the GI value, according to the American Diabetes Association.
Expert Insight
The American Diabetes Association has found that the amount of carbohydrates in a food is still the best predictor of how much blood glucose will rise when this food is eaten, and recommends that carbohydrate counting be the main tool for controlling glucose levels in diabetics. The glycemic index is best used in combination with carbohydrate counting for those who need to further refine their food choices for even better blood glucose control, rather than as a stand alone tool.
