What Is The Glycaemic Index?

The Glycaemic Index by Jane Thurnell-Read

It used to be thought that complex carbohydrates (starches) were absorbed more slowly than simple carbohydrates (sugars). This was based on the assumption that as complex carbohydrates had larger molecules they would be harder to digest. The technology has only become available recently to check out this assumption that was taught as fact.

Work by Professor David Jenkins has shown that some starch foods give an equivalent blood-sugar response to some simple sugars. From this work he developed the glycaemic index. This index is a measure of food’s effect on blood sugar. Glucose has a G. I. Value of 100. Foods with a high glycaemic index will tend to lead to a rapid surge in blood sugar levels and mean that the pancreas has to work harder. If you are working to stabilise blood sugar, it may be very important for you to understand about the glycaemic index.

The glycaemic index offers some surprises for health conscious people. Rice cakes have a glycaemic index of around 80, and parsnips are over 90. Both of these are much worse than sugar in this respect, although sugar is obviously much worse in many other respects. Now I’m not saying throw out your rice cakes and parsnips, but you may need to restrict them if you want to stabilise your blood sugar. Eating foods with a low glycaemic index will help your body to do this.

Here's the glycaemic index of some common foods:

Apple Juice: 40
Apple: 38
Apricots, dried: 31
Apricots, fresh: 64
Banana: 55
Biscuits: 62-79
Bread, rye (pumpernickel): 41
Bread, white: 70
Bread, wholemeal: 69
Breakfast cereals, sweetened: 77- 84
Broad beans: 79
Buckwheat: 54
Bulgar: 48
Cakes: 44-76
Carrots: 49
Cherries: 22
Chick peas: 33
Chocolate: 49-68
Croissant: 67
Grapes: 46
Honey: 58
Kiwi Fruit: 52
Lentils: 28
Low fat yoghurt: 33
Lucozade: 95
Milk: 27-32
Orange juice: 46
Orange squash: 66
Orange: 44
Parsnips: 97
Pasta: 32-41
Pastry, flaky: 59
Peaches: 42
Peanuts: 14
Peas: 48
Pineapple: 66
Pitta Bread: 57
Porridge: 42 (not one-minute variety)
Potato crisps: 54
Potato: 56-83
Raisins: 64
Rice Cakes: 82
Rice, Basmati: 58
Rice, brown: 76
Rice, white: 87
Ryvita Rye Crispbread: 69
Sausages: 28
Sports Drinks: 70-80
Sucrose: 65
Sultanas: 56
Sweet corn: 55
Yoghurt, low-fat fruit: 33

Have a look at some of the books that list the glycaemic index of foods. I recommend Glucose Revolution by Jenny Brand.