Have you seen the eye-catching ad for Diabetes Forecast Magazine? The ad pictures a brownie and a baked potato placed side by side and asks which one will raise your blood sugar more. If you haven’t seen this ad, you might be in for a shock.
According to the Glycemic Index (GI), the correct answer is the baked potato. You are probably asking yourself how that could be true. Well, it all started in 1981 when Canadian researcher Dr. David Jenkins conducted research demonstrating that not all carbohydrates are equal in their effect on blood sugar levels. Through Dr. Jenkins’ research, the concept of the Glycemic Index was born.
What is the Glycemic Index (GI)?
The GI is a way of ranking carbohydrate foods based on how much of a rise in blood sugar they produce during the two to three hours after you eat them. Foods with a higher GI number produce a higher rise in blood sugar. As a result, the body must produce more insulin. Lower GI foods produce less of a rise in blood sugar, and, therefore, less insulin needs to be produced.
What are the Benefits of a Low GI Diet?
The benefits of low GI diets appear to be related to lower circulating levels of insulin and may include:
The Glycemic Index and Diabetes
Diabetes Care recently published a review on the results of 14 studies testing the glycemic index in people with diabetes. The results showed that those subjects who ate a low GI diet saw a reduction in after-meal blood sugar levels equal to those seen with some types of diabetes medications.
Which Foods Have a High GI, and Which Have a Low GI?
Over 750 different types of carbohydrate foods have been tested and given a GI value. The surprise is that many sweet-tasting foods like grapes, bananas, strawberries and peaches have low GI values. These are the very foods individuals with diabetes may be avoiding for fear that the sweeter-tasting foods will harm blood sugar control
Conversely, many traditional low-sugar foods consumed by people with diabetes like cornflakes, pretzels, Cheerios and baked russet potatoes have a high GI. For the sake of simplicity, it is best to think of a food in terms of whether it has a low, moderate or a high GI.
The table below lists some examples of typical carbohydrate foods and their corresponding Glycemic Index:
|Low GI (55 or less)||Moderate GI (56-69)||High GI (70 or more)|
|Apple (38)||Corn (56)||Bagel (72)|
|Steamed Brown Rice (50)||New Potato (59)||French Fries (75)|
|Green Peas (48)||Puffed Wheat (67)||Mashed Potato (70)|
|Peanuts (23)||Shredded Wheat cereal (67)||Pretzels (83)|
|Yogurt (plain14) (fruit 36)||Whole grain bread (68)||White Bread (70)|
To find a listing of the GI of many carbohydrate foods, click here.
Tips for Using the Glycemic Index:
Remember that a food with a lower GI is not always a healthy choice, as is the case with the brownie. If you eat too many carbohydrates, even from a lower GI food, you may still have a high blood sugar reading.
Many low GI foods, such as fruits, vegetables and beans, are excellent carbohydrate choices. Using these low GI foods not only improves blood sugar control, but it may also help you reduce the risk of cancer and heart disease.
Regardless of what type of food plan you follow, you can always begin substituting high GI foods with lower ones -- and begin to reap the benefits of a low GI lifestyle
Glen says: Please consult your physician before stating any diet.