What Is Glycemic Load (GL)?

Glycemic Load is a further refinement of the idea of Glycemic Index, and is much more practical for use in real life as it measures the actual effect on your blood sugar of eating one portion of something. This concept is much more useful in controlling your blood sugar and your weight.

Glycemic Index (GI) is based on the idea that different carbohydrates have a different effect on your blood glucose level as they are absorbed into your body. The higher the Glycemic Index (GI) the more rapidly the carbohydrate is absorbed, and the more glucose appears in your blood. Slowly absorbed carbohydrates have a lower GI index as they are more slowly absorbed, and the body can cope better with them, so that they don’t raise the blood glucose levels so much. It is the sudden rise in blood glucose that causes the body to store this glucose and fat, and this is when you put on weight. It is also the time when people with diabetes have problems controlling their blood sugar levels, as the body is already struggling to keep blood glucose under control, so diabetics should be eating foods with a low Glycemic Index (GI) anyway.

The Glycemic Load (GL) takes into account not only the Glycemic Index (GI) or how quickly the carbohydrate is absorbed, but also takes into account the amount of it that you eat, and so is a much better indicator of its actual effect on the body.

To calculate the Glycemic Load (GL) , remember that the Glycemic Index (GI) is the blood glucose effect of 100g available carbohydrate compared to 100g of glucose, so divide this by 100 to give the glucose effect of 1g of available carbohydrate, and then multiply it by the amount of carbohydrate actually in one portion of food. Fortunately you don’t have to do this calculation yourself, as all the books listed will do this for you.

So the Glycemic Load (GL) for one medium carrot, weighing 80g, containing 6g of carbohydrate, with a Glycemic Index (GI) of 47 would be, 47 divided by 100, multiplied by 6 = 2.82 which we will round to the nearest whole number and call 3. GL greater than 20 is considered high, a GL of 11-19 is considered medium, and a GL of 10 or less is considered low

The best way to think about them is to look at Glycemic Index (GI) as a food quality measurement and to think of Glycemic Load (GL) as a measure of how much weight you will put on by eating one portion. This is a much better way than looking at the calories you eat, because this actually measures the way those calories effect your body, because not all calories are created equal.

Using Glycemic Load To Control Your Weight

Glycemic Load can be used to control your weight by controlling your blood sugar level in a very practical way, either to lose weight, maintain your weight or even if you are diabetic.

Counting the Glycemic Load (GL) units you eat throughout the day is the best way to watch your weight, so that you either keep it at the level you want, or lose weight.

For example, Patrick Holford in his Low-GL Diet books recommends eating no more than 50 GL units a day, or no more than 40 if you want to lose weight. These are best divided through the day as smaller meals, rather than eating larger meals, as this in itself improves your blood glucose profile, and helps to control your weight.

Foods with a Glycemic Load of below 10 are generally considered good, those of 15 or more are considered bad, and 10-15 are OK. Here are some examples of typical portions you are likely to eat

Below is a Gl Table for some common Foods