The Glycemic Index (GI) has been used for many years as guide to the rate at which carbohydrate content is absorbed into the blood stream for energy, and the effect it has on raising blood sugar levels. The Glycemic Index (GI) is a measure of the degree to which a carbohydrate is likely to raise your blood sugar (glucose) levels. The scale is 0 to 100 (based on either white bread or glucose), with 0 being low and 100 being high. The GI compares equal quantities of carbohydrates and provides a measure of carbohydrate quality but not quantity. So the drawback with GI ratings is that they are not based on commonly-consumed portion sizes of foods.
For example, only about 7% of a carrot is made up of are useable carbohydrates. But because a 50g carbohydrate content is employed as the standard measure for a GI rating of individual foods to show how fast blood sugar level are raised, a larger than normal food portion is used for the GI calculation. In the case of carrots, for example, the amount is equivalent to 1.5lbs – far more, of course, than people normally eat as a snack or part of a meal.
As a result, the GI rating often overstates relatively small carbohydrate content in a food item like a carrot.
The reverse is also true, i.e. the glycemic effects of foods containing a high percentage of carbs like bread, can often be understated under the GI system.
Therefore we recommend using the Glycemic Load index with calculations based upon realistic food portions. GL ranks food according to the effects of actual carbohydrate content in a standard serving size of food.
Glycemic Load (GL) index
Harvard University scientists introduced the concept of Glycemic Load (GL). This measure gives a more accurate reflection of the blood sugar effects of a standard food portion. In short, the GL of a typical serving of food is the product of the amount of available carbohydrates in that serving and the glycemic index of that food.
In practical terms, the higher the GL of a food, the greater the expected rise in blood glucose and the greater the adverse insulin effects of the food. Foods with a GL of 10 or below would be presumed to be less detrimental to health, while those with a GL of 20 and above would have more detrimental effects. Long term consumption of foods with a high glycemic load appears to be linked to a greater risk of obesity, diabetes, and inflammation. These, it also now appears, may even have negative effects on the brain that we are only beginning to understand.
Carbohydrates are not always our enemy, they can be utilised for our personal gain with fat loss or building lean muscle tissue.
Nutrition is a great tool… When applied correctly !