Low GI Diet
The glycemic index (GI) scale starts at 100, which is the GI of pure glucose. Glucose is given this rating because glucose does not need to be broken down by the body to be absorbed into the bloodstream. This means glucose causes a quick rise in blood sugar levels. Other foods are also ranked by the extent they raise blood sugar levels after they have been consumed.
More work has been done on the Glycemic Index (GI) and diets based on low GI by Dr Jennie Brand-Miller and her researchers at the University of Sydney, Australia.
It should also be noted that if a food that has a high GI is eaten with a food that has a low GI, the net GI of the meal becomes medium GI.
Low GI: 55 or lower
Medium / Moderate GI: 56 – 69
High GI: 70 or higher
In addition to the glycemic index, there is also the glycemic load (GL), which takes into consideration the portion size of the carbohydrate food together with it’s glycemic index as this has an impact on the level of glucose when the foods is eaten. A lower GI food can have the same GL as a higher GI food if a larger portion of it is eaten.
The glycemic load is defined as follows:
- Low GL foods: All high fibre fruits and vegetables (except potatoes), 80g bran cereal, 3/4 cup cooked legumes, 1 cup skim milk, 80g nuts, 2tsp sugar and GL is between 0-10
- Medium GL foods: 1 cup pearled barley or oats, 3/4 cup brown rice or bulghur, 1 slice wholegrain bread, 1.25 cup cooked wholegrain pasta, 1 glass unsweetened freshly squeezed juice and GL is between 11-19
- High GL foods: 1 cup cous cous or basmati rice, 1 baked potato, small french fries, 1.25 cup cooked white pasta, 1 cup cranberry juice drink, 1 bowl processed breakfast cereal (cornflakes), 10 large or 30 small jellybeans and GL is over 20
Glycemic load (GL) is just as important as glycemic index (GI) and is calculated differently to GI. Glycemic load is the quantity of carbohydrates (and the effect of that on the blood sugar and insulin levels), whereas the glycemic index is the quality of the carbohydrate (and the effect on blood sugar and insulin levels). The glycemic load is calculated by multiplying the glycemic index by the amount of carbohydrate (in grams) of the food and dividing the total by 100