glycemic load

Well this is different. I don't think we've had that one before but am I missing the point? Glucose is about as carb as it gets so if a GL unit is the same as one gram of glucose I think you've answered it.

Dear Southbeds,
I'm not entirely sure as to what your question relates to, but this might explain things.
In the late 1990's food items were tested to see what their response would be (Non- Diabetics were used in the testing) and they were given 100 gms or 100 ml of the food/drink item and following on from this their blood glucose response levels were measure over a set time period. The results were then compared to their taking the 'Standard' reference item 100 gms of pure 'Glucose' from the two readings it was then possible to estimated the B/G rise and this was then allocated a Gi rating (Glycaemic Index - Glucose being 100 and the common reference, though some tables used White bread as the reference - White bread having a Gi of 70)
This form of measurement was later amended as it failed to take into account what would in reality have been a realistic portion, so a new revised system was introduced that took into account a realistic portion size and the tables for this were referred to as being GL (Glycaemic Load).
As a diabetic it is much better to use GL tables rather that Gi tables (though they are still useful for guidance purposes)
I hope this sheds some light on your question, though I don't think you can directly compare GL with Glucose directly as you might possibly be thinking, although they are related.

The glycaemic load can be calculated as follows.

Glycemic load = the total grams of carb x the GI of that food, divided by 100. The lower the better.

0-10 is considered low
11-19 medium
above 20 high.

As 'Lazybones' says the GI is a ranking of the effect a fixed amount of carbohydrate in a food has on glucose levels. (they actually normally use 50g carb or much less in a food that is less dense in carbs)
The GI is therefore a measurement of carb 'quality' and the GL using the formula quoted by Bluetit is the amount of carbs in the portion of food you are going to eat ,adjusted for it's glycemic 'potency'


If you eat an apple with 15 g of carb and a GI of 40 then it's GL would be 6 (GL = 40 x 15/100 = 6 g)
If you have 2 apples with 30 g of carb and a GI of 40 then it's GL would be 12(GL = 40 x 30/100 = 12g)


The biggest data base is the one from the University of Sydney. Here's one example taken from it
Red lentils, split dried boiled for 20 minutes
GI of the food is 21
weight of the food tested (ie after cooking for 20 min, not dry weight) 150g
amount of carbs in the food 18g
the GL of that amount 4g
(so if you ate a 75g portion then it would have a GL of 2, if you ate 300g it would have a GL of 8 etc)*

The data base is here http://www.glycemicindex.com/foodSearch.php
Very few people are going to work out the Glycemic load of everything they eat . If you tend to eat a similar amount of carbohydrates in a meal then choosing foods that have a lower GI will naturally mean that the glycemic load is also lower

*(if you click on a food in the data base you can find details of the testing done on that food
The test on lentils was done in 2005 in the UK with non diabetics. It was a small sample of only 8 . The data base does contain quite a lot of foods tested on diabetics because it was originally developed for use in diabetes. T2s will have higher glucose levels than non diabetics overall but when researchers have compared the responses with T2s and non diabetics they find a good correlation in the ranking ie the same types of foods will normally result in higher levels in both T2 and non diabetics.)