The glycaemic index (GI) is a system of ranking carbohydrate foods, based on their effect on our blood glucose (or blood sugar) levels. The GI ranks foods from 0 to 100. The higher the GI value, the greater the blood sugar response. So, low GI foods raise blood sugar levels just a little, medium GI foods raise blood sugar levels moderately, and high GI foods raise blood sugar levels quite high and quite quickly.
The ranking of GI foods is as follows:
- Low GI foods - less than 55.
- Medium GI foods - 55 to 70.
- High GI foods - more than 70.