The glycemic index, or GI, can be a useful tool for diabetics who must keep their blood sugar under control. Though somewhat controversial, the GI gives you an indication of how quickly the foods you eat will spike your blood sugar. When planning your meals, consult the glycemic index in addition to carb counting or other method your health care provider or dietitian advises.
Glycemic Index History
The GI was first introduced in 1981 and has received varying amounts of support. For example, the American Diabetes Association and Harvard's Joslin Diabetes Center acknowledge its usefulness in helping diabetics choose what foods to eat, while the American Dietetic Association sticks to the more traditional advice of counting total carbohydrate intake. Public health officials from the Centers for Disease Control and Prevention and the National Institutes of Health make little reference to GI in standard recommendations to the public.
How GI Works
According to Joslin, the index specifically indicates the after-meal response your body has to a carbohydrate when compared to a standard amount of glucose. Many factors play a role in how your body will respond, including your age, level of physical activity, how much fiber is in the food, how the food was cooked, how much fat, how much processing the food has undergone, how quickly you generally digest food and whatever else you are eating with that food. According to dLife, high-GI foods are quickly digested carbs, sometimes called "gushers" that rapidly enter the bloodstream and cause a surge of glucose. Your body responds with a gush of insulin to shuttle the glucose into your muscles and fat cells. This often results in low circulating blood sugar, leaving you with hypoglycemia. Many people try to overcome the feelings associated with hypoglycemia by eating another high-GI food, causing another surge and a vicious cycle that leaves you hungry and tired and packing on the body fat. On the other hand, low-GI carbs digest slowly, so there's no overcompensation by insulin. You get a constant supply of energy and therefore no abnormal fat storage.
GI Scores
The University of Sydney maintains a database of carbohydrates and the official website for the GI. You can use the database to look up foods you want to eat to get a score that determines whether it is high, medium or low impact in terms of raising your blood sugar. A food that scores 70 or higher is considered high, 56 to 60 medium and 55 or less is considered low. High-GI carbs tend to be white, starchy and processed foods like potato chips, cookies and other desserts and highly refined packaged goods. Low-GI foods tend to be nutrient-dense natural foods like high-fiber items, whole grains, vegetables and legumes.
Research
Australian researchers publishing in the August 2003 "Diabetes Care" conducted a meta-analysis comparing the results of several studies on the effects on consuming a low-glycemic diet by diabetics with those who had conventional diets and those who had high-glycemic diets. They found that the low-glycemic eating had a "small but clinically useful" effect on participants' glycemic control. They said people with diabetes who eat low-GI foods get the same benefits offered by diabetic drugs that attempt to control after-meal blood sugar spiking.
Diabetes in the United States
According to the CDC's National Diabetes Fact Sheet 2011, diabetes affects 25.8 million people. That's slightly more than 8 percent of the entire U.S. population. The CDC says 7 million have diabetes and don't know it. It is the seventh leading cause of death, and public expenditures for diabetes care cost $174 billion in 2007. Diabetes is an epidemic, and the CDC estimates that one in three adults will have diabetes by 2050 if current rates continue, according to the CDC.
References
- American Diabetes Association: Glycemic Index and Diabetes
- "Diabetes Care"; Low--Glycemic Index Diets in the Management of Diabetes; Jennie Brand-Miller; August 2003
- dLife: Glycemic Impact 101
- dLife: The Glycemic Index; David Mendosa; Dec 7, 2009
- Joslin Diabetes Center: The Glycemic Index and Diabetes
- CDC; National Diabetes Fact Sheet, 2011
