What do GI and GL mean, and what is the difference?
‘GI’ means Glycaemic Index, and it is a measure of how quickly (or slowly) a food raises blood sugar levels. A low GI value (below 55) means that a food slowly raises blood sugar levels; a high value (above 70) means levels are quickly raised. Glucose has a GI rating of 100; plums have a low GI rating of about 45. ‘GL’, a fairly recent concept, means Glycaemic Load, and refers to the quantity and quality of carbohydrate in a food or meal portion, and also takes into account the GI value. The more carbohydrate there is in a food, the higher its GL value. The GL value can be viewed as the ‘power’ behind the GI – so a high GI/high GL meal is not good news! Aim to have no more than a daily GL total of 100.
