What is Glycemic Index and Glycemic Load?

The idea of the Glycemic Index (GI) has been out for many years, but nonetheless a lot of people will still see GI and go: “G.. What?… Uh?”

In the same time we learn that managing insulin levels is one of the most essential things (if not the most essential) for effective fat loss. So how do we manage these levels if we don’t know about GI?

Moreover, GI by itself is not an accurate estimate of whether a particular carbohydrate food is acceptable for fat loss (and good health in general) or it’s a “stay away from it” type.

There is another value that goes hand in hand with the GI. It is called Glycemic Load (GL).

Let’s touch on these two briefly to see what is their application in the nutrition planning
of the contemporary athlete (and not only..).

GI is a measure of how fast a carbohydrate food enters your blood stream in the form of blood glucose. Each carbohydrate food has a GI value assigned.

It is widely accepted that simple sugars have higher GI, while complex carbs have lower.
Still, there are instances where a complex carb will have very high GI and a simple carb –
very low.

Such is the case of maltodextrin (a “complex” carb with GI of about 120), and dextrose –
a simple sugar, also known as glucose.

Conforming to the “insulin levels management for fat loss” concept we should always strive
to eat carbohydrate foods with GI lower than 55. Higher than 70 will trigger sudden high
insuline levels and promote fat storage.

(Just for your information glucose is assigned a GI value of 100. It is used for the test
carb food when determining the GI of other carbohydrate foods.)

Good so far, but the thing is GI doesn’t tell us how much carbs there are in a serving of
a particular food. Here is where GL comes to play.

GL is the GI divided by 100 and multiplied by the grams of effective carbs in a serving of
a carbohydrate food (Uh..?). The values for GL range from 1 to 20 – lower values being better.

Values of over 10 are not desirable for good health management and fat loss promotion.

Why should we look at the GL value also, when making a decision whether a carb food is good for our meal plan or not?

According to the GI index alone some carb foods appear to be in the “black list”, which calls
for refraining from including them in our menu.

Such is the case of the (poor) watermelon for instance. Its GI value is 80(!) but its GL value is less than 8. So, clearly watermelon falls in the group of the desired foods it turns out.

Think about it for a moment. If you ate a 200 gr. wedge (without the seeds) for dessert, this would only give you some extra 10gr. of carbs. How much should you eat so that you really ingest the amount of sugars that will put your fat loss efforts in jeopardy? 2LB? Or even 4LB?

Any way, I made my point.

You now know which means what. Always keep in mind that you should look at both indexes when deciding if a carb food belongs to your menu or not.

You can find the GI and GL values of quite an extensive list of foods by visiting the official
web site of the GI and GL. Choose “GI Database” from the menu on the left and type in your food.

Here is their web site.

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