What is Glycemic Index
Glycemic Index is a measure or a scale that gives information about how foods, especially carbohydrates affect blood sugar. It lets you know how much each gram of the carbohydrate you are consuming raises blood glucose to what level.
The lower the rank of the food, the least it affects blood glucose. GI is determined on the basis of the rate of release of carbohydrate into the blood. For example: Foods containing carbohydrates that breakdown quickly release glucose very rapidly in the blood are placed highest on the GI index while those carbohydrates that breakdown slowly, release glucose slowly and are ranked low in the GI.
Relationship between Glycemic Index and Glycemic Load (GL)
The diet of a person or body’s response will depend not only GI ranking but also on GL. Glycemic load is the measure of the amount of carbohydrate in the food.
The standard formula for calculating GL is
GL = GI/100 x Net Carbs (Net Carbs = Total Carbohydrates minus Dietary Fiber)
Significances of Glycemic Index
We shall explain you the main areas where Glycemic Index plays an important role on our health.
1.GI and Diabetes
Diabetic patients are often asked to follow a GI chart for selecting foods that will prevent rise in blood sugar. Since the chart lays out the foods containing both harmful as well as useful carbs, they can plan their meal by eliminating those foods ranked high in the index while incorporating the lowest ranked foods in their diet. This way blood sugar is gradually lowered and one becomes less dependent on medicines
2.GI and Weight Loss
The principle is similar for losing weight as well. Stop eating foods with high GI and form your diet properly with those low ranked GI foods. This way you will get the good carbs for energy.
3.GI and Cardiovascular Disease
This information applies to everyone. A carb rich diet placed high in GI index makes you susceptible to heart disease. Not only sugars are released rapidly in your blood stream but those food items are rich in LDL (bad cholesterol), which increases your chances of developing heart diseases. Thus, you can accordingly choose the foods for a better hearth health.
Key Components of GI
According to mayoclinic, foods ranked by the Glycemic Index are given the following scores:
- High: 70 and up (e.g. white flour, corn flakes, white rice, potatoes, bagels)
- Medium: 56 to 69 (e.g. pita bread, brown rice, dry fruits, cranberry juice, banana, ice cream)
- Low: 55 and under (e.g.beans, seeds, vegetables, whole grains, sweet fruits)
- According to whfood.org, a normal, healthy adult is advised to form their meal in the following ways
- Main components should have a GI of no more than 70
- Half of all components should have a GI below 50
Limitations of Glycemic Index
- The methods of preparation of various foods considerably affect the GI value and GI doesn’t take the food processing or cooking method in consideration. Therefore, the GI value may vary.
- In reference to the point explained above, the GI will definitely differ and depend on the method of cooking, the variety of the food, addition of extra ingredients and combination of other foods in the GI or outside.
- The response towards digestion of carbohydrate differs from one person to another. Similarly, the insulin response of body also varies. Thus, depending completely on the GI index for planning meals is not very wise.
- Multiples entries for one food give rise to confusion. The entry of food and the types are also limited. So you may not find the food that you are going to consume in the GI list.
To conclude, we can say that you can rely on GI to a certain extent. Definitely you can choose your foods in a better way and have small meals instead of large portions. However, it’s always advisable to consult your doctor before making your diet plan if you are suffering from health complications.
Written by: Saptakee sengupta
Date last updated: January 03, 2015