The glycemic load helps people understand how much carbohydrate is in food and how it could affect blood glucose levels.

For people with diabetes, the glycemic load can be useful to assess which foods are most likely to maintain glycemic control.

Diabetes and the glycemic index

The glycemic index (GI) is the basis of working out a food’s glycemic load. It ranks food depending on how quickly it is broken down in the body to form glucose.

Following a low-GI diet is suitable for people with diabetes as it incorporates food that is more slowly converted into energy.

This means blood glucose levels will not rise imminently after eating. High-GI foods, meanwhile, are quickly broken down into glucose.

While the GI enables people to make good food choices, the glycemic load can help you work out how different carbohydrate portions compare with other foods in raising blood sugar levels.

The glycemic index is not something can usually be worked out, but thankfully, there are tables with the glycemic index already worked out.

  • Glycemic index tables  (Link to say Glycemic Index page –as long as it does indeed have a table of GI values)

How do you work out the glycemic load?

To calculate the glycemic load, you will need to know the GI of the food product, and the amount of carbohydrate in that portion.

Then, multiply the GI value by the amount of carbohydrate (grams) in the product, and divide by 100 (GL = GI x carbohydrate / 100).

Example: White rice and couscous

If you have a 130g portion of rice (when cooked), this will provide 40g of carbohydrate. The GI of white rice is 85.

On the other hand, a 200g serving of couscous will provide 45g of carbohydrate. The couscous has a GI value of 60.

  • Glycemic load of white rice portion
    = GI x carbohydrate / 100
    = 85 x 40 /100
    = 34
  • Glycemic load of couscous portion
    = GI x carbohydrate / 100
    = 60 x 45 /100
    = 27

This is why the glycemic load is so useful. Even though there is less carbohydrate in the smaller portion of white rice, the couscous has the lower glycemic load, and is less likely to cause a sharp spike in blood glucose levels.

Which foods have a high glycemic load?

As defined by the University of Sydney, the glycemic load is classed into three groups: low, medium and high.

  • Low glycemic load (low GL): 0 to 10
  • Medium glycemic load (med GL): 11 to 19
  • High glycemic load (high GL): 20 and over

Foods that can be referenced in these groups include:

  • Low GL: Milk, cashews, peanuts, whole-grain breads, tomato juice
  • Med GL: Oatmeal, sweet potato, fruit juices with no added sugar, rice cakes, whole-wheat pasta
  • High GL: French fries, pizza, candy, low-fiber cereals

How can I use the glycemic load?

While calculating the glycemic load of food may not always be practical for some people, it can be helpful in assessing which foods can improve your diabetes control.

If you have blood testing supplies, you can experiment on yourself to see how particular glycemic loads affect your blood glucose levels afterwards. A good way to assess the effect of a particular meal is to test your blood glucose before eating, two hours after eating and then four hours after eating.

In turn, you may find it easier to anticipate blood sugar changes, but this can vary from person to person.

Moreover, if you are uncertain regarding trying a new food, comparing its glycemic load to previous meals you know have raised your blood sugar can help you make your decision.