Getting to Grips with Glycaemic Load

Glycaemic Index & Glycaemic Load

Have you seen the terms ´GI Index´ and ´glycaemic load´ scrawled on so many supermarket products that you feel like you ought to know what they mean? Let us give you the gist of GI, to take a glycaemic load off your back. The glycaemic index (GI) is a rating used to measure the level of sugar circulating in the blood in response to a carbohydrate meal or snack. The higher the GI number, the greater the rise in blood sugar. Low GI foods cause smaller rises in blood sugar, while higher GI foods trigger a big spike in blood sugar; hence the “low GI rating” promises on cereal boxes galore. It`s always better to know what to look out for yourself, rather than believing the box of sugar-coated cornflakes, which promises to keep you going throughout the day.... more likely to keep your blood sugar levels going bananas throughout the day! To that end, here are the GI benchmark ratings to bear in mind:

Glycaemic Index

High GI Rating	Medium GI Rating	Low GI Rating
70 or more	56 to 69	55 or less

More recently, glycaemic load (GL) has been developed as a more complete measure of the impact of dietary carbohydrate on the body. It is important to understand both GI and GL to understand a food’s effect on blood sugar, so GL calculations take the GI rating into account as well. The formula for working out the GL of a food is: GI multiplied by the amount of available carbohydrate in the food, then divided by 100.

Glycaemic Load

High GL Rating	Medium GL Rating	Low GL Rating
20 or more	11 to 19	10 or less

Some examples of GL are:

Carrots have a GI of 47, a carbohydrate content of 7.5% and a GL of 3.5
Boiled white rice has a GI of 64, a carbohydrate content of 24% and a GL of 15.4
White bread has a GI of 95, a carbohydrate content of 50% and a GL of 48

As discussed in our previous article, “Carbs: The Good, The Bad, and the Ugly", other factors that effect GI and GL include fibre, fats and proteins. Fibre, which is also a carbohydrate, is digested more slowly than fibre-less carbohydrates. As illustrated above, this has a positive effect on GI and GL ratings. And yes, that does mean that your dad`s stogy-looking, fibre-rich bran cereal
is probably a better, lower GI choice of breakfast than Frosties – no matter how energetic Frostie the Tiger`s roar may appear to be. “Remember that raw vegetables are a great source of carbs & loaded with fibre too!” Fats and proteins also have their place in effecting GI. Since the digestion of fats is slower than carbohydrates, when fats are combined with carbohydrates, this slows down the digestion of the carbohydrates. The same goes for adding protein to a carbohydrate meal – the body takes more time to digest the meal and to release its energy. This means that combining good quality fats and protein to each meal is a great way to minimise fluctuations in blood sugar levels and energy, while supporting insulin levels and assisting with weight management. Controlling insulin levels goes a long way to maintaining optimal health, since chronic insulin over-secretion (and resulting insulin resistance) is linked to so many chronic health conditions seen in the western world today (e.g.: diabetes, obesity, heart disease, Alzheimer's, cancer and others). Gettings to grips with GI & GL may help loosen your grip on those cookies!