Glycaemic index (GI)

Ranking potatoes in the GI scale
The Glycaemic Index (GI) ranks carbohydrate foods based on the speed at which they enter the bloodstream and the immediate effect on blood sugar levels. The faster the blood sugar response appears in the bloodstream after eating a food, the higher its GI ranking.

A GI of less than 55 is considered ideal
Potatoes have a GI of 65 - 101 (depending on the variety and cooking method). However when they are eaten with other foods which contain fat, protein or fibre they are absorbed more slowly.

GI ranking is based on portions of food containing 50g of carbohydrates, but does not consider that the carbohydrate content of food varies widely e.g. three potatoes would provide 50g of carbohydrates but you would have to eat a whole watermelon or 700g of carrots to get the same quantity of carbohydrates.

The glycaemic load (GL) ranking was created to overcome this limitation. It is a way of ranking foods according to GI and portion size. This system is recognised and accepted as a more accurate system of measuring the blood glucose response of foods.

It is widely acknowledged that nutrient dense food found to have a high GI, such as potatoes, play an important role in a diet and that high energy, nutrient poor, low GI foods should be consumed in moderation.

Potatoes make up for their high GI because they are nutrient rich and play an important role in a diet.