Diabetes is a general term for a metabolic disorder characterized by high levels of glucose in the blood. In healthy individuals, glucose is properly regulated by a variety of physiological processes. Because diabetics have disrupted physiological processes, it is important to follow a diet, such as the glycemic index, that can help keep blood sugar levels from getting too high.
Blood Glucose
When you eat carbohydrates, your body breaks down them down in simple sugar molecules, called glucose. Glucose, which is your body's preferred source of energy, travels through your digestive tract until it is finally absorbed into the bloodstream. In healthy individuals, glucose in the bloodstream triggers the release of insulin from the pancreas. The insulin binds to the glucose and helps the cells use it for energy. Diabetics experience problems with the way their bodies respond to glucose.
In Type 1 diabetes, the insulin-producing cells in the pancreas are destroyed and insulin is not released when glucose enters the bloodstream. In Type 2 diabetes, glucose triggers the release of insulin, but the cells are resistant to its effects. Both types of diabetes result in prolonged periods of elevated glucose in the blood.
Glycemic Index Basics
The glycemic index diet is based on the theory that different types of carbohydrates have different effects on your blood sugar levels. Some carbohydrates move through your digestive system quickly. These carbohydrates cause blood glucose levels to rise rapidly and dramatically. Other carbohydrates move through your digestive system slowly. These carbohydrates do not affect blood glucose levels as dramatically. Instead, blood glucose levels rise slightly but remain steady, for the most part. When following a glycemic index diet, the idea is to eat the carbohydrates that move through your digestive system slowly. These carbohydrates are considered low on the glycemic index scale.
Glycemic Index Scale
On the glycemic index scale, foods are ranked on a scale from 0 to 100, based on their potential to raise blood sugar. Foods ranked from 0 to 55 are considered to have a low glycemic index. These foods, which include apples, peas, milk, beans and lentils, should provide the basis of a glycemic index diet. Foods ranked from 56 to 69 are considered medium glycemic index. These foods include corn, bananas and pineapple and should be eaten in moderation. Foods that are ranked from 70 to 100 are high on the glycemic index. These foods have the most dramatic effect on blood sugar and should be avoided as much as possible. Some examples of foods with a high glycemic index include rice, white bread, potatoes and watermelon.
Proposed Benefits
MayoClinic.com notes a number of health benefits that have been associated with following a glycemic index diet. In addition to keeping a diabetic's blood sugar levels steady, these benefits include reducing the need for diabetic medication, such as insulin, and controlling appetite and delaying hunger, which can prevent weight gain.
Considerations
It is important to note that the glycemic index diet also has possible problems. Foods on the glycemic index scale are ranked individually, rather than in combination with other foods. Most people eat a variety of different foods at a meal, rather than just one type of food. Different combinations of food can have different effects on blood sugar. The glycemic index scale also doesn't specify portion sizes or food preparation techniques. Larger portions of foods and certain cooking methods can change the food's effect on blood sugar. MayoClinic.com also notes the glycemic index scale does not consider the nutrient content of the food, only the effect on blood sugar. Because of this, foods that are high in calories or fat, but have no nutritional value, might be considered good to eat.
