What is the Glycaemic Load (GL)? The concept of the glycaemic load is one that is becoming more commonly used and referred to in the food industry. How often have we picked up a food product which has the words Glycaemic load or glycaemic index written in big bold letters? We may have all heard of the glycaemic index (GI) – a value that is obtained by measuring the effect that a carbohydrate containing food has on blood sugar levels, compared to the effect of the same amount of pure sugar, on blood sugar levels. However, the problem with the GI is that is doesn’t provide an accurate picture of the entire blood sugar raising potential of the food. The blood sugar response depends on both the quantity and quality of carbohydrates consumed. The glycaemic load (GL) is an extension of the GI, taking into account the total amount of carbohydrates as well.
How is the GL Determined?
The GL is obtained by multiplying the GI value of the food by the amount of carbohydrate the serving of food contains, divided by 100. If we take a common fruit such as an apple for example, the GL is determined as follows:
GI of a standard apple = 40
Carbohydrate content of a standard apple = 15
GL = (40 x 15) / 100 = 6
Generally, foods with a low fibre content and high carbohydrate levels have high GI and GL values, whereas those with high fibre contents have lower GLs. Many factors affect the GL of a food. These include: the types of sugar and starches in the food, the way it is prepared, – fat, fibre and carbohydrate content, and serving size.
The following ranges are usually applied to determine the GL of a particular food:
- Low GL – 10 or less
- Medium GL – 11 to 19
- High GL – 20 or more
The following values are applied to define the GL per day:
- Low GL – less than 80
- High GL – more than 120
Foods with a low GL means that they cause a more steady and lower rise in blood sugar levels. These include many fruits and vegetables.
Foods with a high GL means that they cause a faster and higher rise in blood sugar levels. High GL foods include those such as white rice and refined snack foods such as chips and sweetened drinks.
GL & medical conditions
Clinical studies have shown that the dietary GL is linked to risk factors for heart and major vessel disease, diabetes and obesity. By consuming foods that have a low GL, there is an overall slower and lower rise in blood sugar levels.
If you suffer from diabetes, the GL has been shown to be a more accurate and reflective predictor on blood sugar levels. By adhering to a diet with a low GL, diabetics can reduce their average blood sugar levels and lower their risks of developing complications such as eye, kidney and nerve damage.
Diets with a high GL value have also been correlated with increased risk of heart and major vessel disease, and directly related to bad cholesterols such as LDL and triglycerides.
For more detailed information on the glycaemic load and it’s clinical application in patient’s lifestyles, visit Glycaemic Load.
Or for more detailed information on the glycaemic index and it’s clinical application in patient’s lifestyles, visit Glycaemic Index.