If you are a diabetic who needs to keep an eye on your blood sugar levels or a dieter who is trying to lose weight, you should become familiar with the glycemic index or GI. The glycemic index may appear complicated, but it is fairly easy to understand and a very useful tool. Please consult your doctor prior to making any drastic changes to your diet, especially if you are diabetic.
Definition
In short, the glycemic index is a quantitative rating scale of how much a food will potentially raise your blood sugar. The Joslin Diabetes Center gives a more comprehensive definition: the glycemic index indicates the after-meal response your body has to a particular food with the frame of reference being a standard amount of glucose. Foods with a high glycemic index, or GI, are thought to have a significant effect on your blood sugar levels, while low-GI foods likely have a smaller effect on your blood sugar levels.
Significance of Blood Sugar
Understanding the significance of blood sugar is mandatory if you are a diabetic and advantageous if you are a dieter trying to lose weight. As the University of Washington explains, when you raise your blood sugar in your body, your body releases insulin to transport the glucose to cells. Diabetics who need supplemental insulin must be careful because too much blood sugar can cause hyperglycemia. In contrast, not eating enough food, or often enough can cause hypoglycemia or low blood sugar. Dieters have interest in the glycemic index because they want to keep their blood sugar levels low. Elevating blood sugar causes insulin release, which can cause fat storage and weight gain.
GI Value
As Florida State University explains, many people think that the more sugar a food has, the higher the glycemic index for that food is. While it is true that carbohydrates usually have the greatest effect on blood sugar levels, several factors go into determining a food or beverage's GI. These factors include how much the food is processed, how long the food is cooked, the kind of carbohydrates that the food contains and the acidity of the food. Foods that are digested quickly or are absorbed quickly generally have a higher GI rating. Conversely, foods that take a long time to digest or absorb generally have a lower GI rating.
High GI Foods, Low GI Foods
Foods that rank atop the glycemic index are foods that are made from finely ground flours such as bread and commercial baked goods, highly processed breakfast cereals, snack foods such as potato chips and pretzels, white potatoes and white rice. Lower glycemic index foods include fruits, vegetables, sweet potatoes, legumes, whole grains, barley, oatmeal, brown rice, whole wheat bread, whole wheat pasta and dairy products. The GI is the scale from which carbohydrates are often separated into "good carbs" and "bad carbs." No carbohydrate is actually good or bad, it purely depends on your fitness goals. If you are dieting and want to keep your blood sugar low to encourage fat loss, high GI carbohydrates will generally be "bad" for that goal. If you are an athlete and need to raise your blood sugar before or after a training session, you may favor high GI carbohydrates in that scenario.
