Glycemic Load
The glycemic load (GL) is a ranking system for carbohydrate content in food portions based on their glycemic index (GI) and the portion size. Glycemic load or GL combines both the quality and quantity of carbohydrate in one ‘number’. It’s the best way to predict blood glucose values of different types and amounts of food. The formula is: GL = (GI x the amount of available carbohydrate) divided by 100.
The glycemic load assesses the impact of carbohydrate consumption using the glycemic index but takes the amount of carbohydrate that is consumed into account. GL is weighted GI value. For instance, the carbohydrate in watermelon has a high GI but water melon does not contain much carbohydrate so its glycemic load is relatively low. A GL greater than 20 is high, a Gl of 11-19 is medium, and a GL of 10 or less is low. Foods that have a low GL almost always have a low GI. Foods with an intermediate or high range GL range from a very low to very high GI.
The usefulness of glycemic load is based on the idea that a high glycemic index food consumed in small quantities would give the same effect as larger quantities of a low glycemic index food on blood sugar. Glycemic Load is the product of the Glycemic Index and the grams of available carbohydrate (GL = GI × available Carb grams). For example, white rice has a somewhat high GI, so eating 50g of white rice at one sitting would give a particular glucose curve in the blood, while 25g would give the same curve but half the height. Since the peak height is probably the most important parameter for diabetes control, multiplying the amount of carbohydrates in a food serving by the glycemic index gives an idea of how much effect an actual portion of food has on blood sugar level.
Glycemic load for a single serving of a food can be calculated as the quantity (in grams) of its carbohydrate content, multiplied by its GI, and divided by 100. For example, a 100g slice serving of watermelon with a GI of 72 and a carbohydrate content of 5g (it contains a lot of water) makes the calculation 5·72/100=3.6, so the GL is 3.6. A food with a GI of 100 and a carbohydrate content of 10g has a GL of 10 (10·100/100=10), while a food with 100g carbohydrate and a GI of just 10 also has a GL of 10 (100·10/100=10).
The GI was invented in 1981 by Dr Thomas Wolever and Dr David Jenkins at the University of Toronto and is a measure of how quickly a food containing 25 or 50 grams of carbohydrate raises blood glucose levels. Because some foods typically have a low carbohydrate content, Harvard researchers created the GL, that takes into account the amount of carbohydrates in a given serving of a food, and so provides a more useful measure. Glycemic Load also has a scale. Low is 10 or less, Medium is 11-19 and 20 or greater is considered High
The glycemic load assesses the impact of carbohydrate consumption using the glycemic index but takes the amount of carbohydrate that is consumed into account. GL is weighted GI value. For instance, the carbohydrate in watermelon has a high GI but water melon does not contain much carbohydrate so its glycemic load is relatively low. A GL greater than 20 is high, a Gl of 11-19 is medium, and a GL of 10 or less is low. Foods that have a low GL almost always have a low GI. Foods with an intermediate or high range GL range from a very low to very high GI.
The usefulness of glycemic load is based on the idea that a high glycemic index food consumed in small quantities would give the same effect as larger quantities of a low glycemic index food on blood sugar. Glycemic Load is the product of the Glycemic Index and the grams of available carbohydrate (GL = GI × available Carb grams). For example, white rice has a somewhat high GI, so eating 50g of white rice at one sitting would give a particular glucose curve in the blood, while 25g would give the same curve but half the height. Since the peak height is probably the most important parameter for diabetes control, multiplying the amount of carbohydrates in a food serving by the glycemic index gives an idea of how much effect an actual portion of food has on blood sugar level.
Glycemic load for a single serving of a food can be calculated as the quantity (in grams) of its carbohydrate content, multiplied by its GI, and divided by 100. For example, a 100g slice serving of watermelon with a GI of 72 and a carbohydrate content of 5g (it contains a lot of water) makes the calculation 5·72/100=3.6, so the GL is 3.6. A food with a GI of 100 and a carbohydrate content of 10g has a GL of 10 (10·100/100=10), while a food with 100g carbohydrate and a GI of just 10 also has a GL of 10 (100·10/100=10).
The GI was invented in 1981 by Dr Thomas Wolever and Dr David Jenkins at the University of Toronto and is a measure of how quickly a food containing 25 or 50 grams of carbohydrate raises blood glucose levels. Because some foods typically have a low carbohydrate content, Harvard researchers created the GL, that takes into account the amount of carbohydrates in a given serving of a food, and so provides a more useful measure. Glycemic Load also has a scale. Low is 10 or less, Medium is 11-19 and 20 or greater is considered High