The Glycaemic Index

Carbohydrate foods

A diet containing carbohydrate foods is important for all people, and for those with diabetes these foods can assist in managing blood glucose levels.

 

Traditionally, carbohydrate containing foods have been classified as either simple carbohydrate (table and fruit sugar) or complex carbohydrate (breads, cereals, legumes and starchy vegetables). It was thought that complex carbohydrates were slowly digested and absorbed into the bloodstream, while simple sugars were assumed to be rapidly absorbed. People with diabetes were therefore advised to eat mainly complex carbohydrate and limit their intake of foods high in simple sugars. More recent research however has found a new way of classifying carbohydrate foods which has proven this information to be outdated.

The Glycaemic Index

The Glycaemic Index (GI) is a measure of the effect different carbohydrate containing foods have on blood sugar levels. It describes the way our body digests and absorbs the food, rather than the structure of the food.

Some carbohydrates are digested and absorbed quickly so they raise the blood sugar level faster and higher. These are high GI foods. Other carbohydrate foods are digested and absorbed more gradually, causing a slower, longer lasting rise in blood sugar levels. These are low GI foods. A number of factors influence the rate of digestion and absorption of a carbohydrate food, it is therefore very difficult to predict the GI of a food just by looking at it.

Research has shown that people eating a lower GI diet can reduce their average blood glucose levels, which is important in reducing the risk of diabetes related complications. It improves the body’s ability to use glucose for energy and improves satiety (feeling of fullness) which can assist with weight management. A low GI diet can also be useful for people with hyperinsulinaemia as the slow, steady release of glucose into the bloodstream does not stimulate over production of insulin. A low GI diet should also be low in fat and salt.

So how do I use this information?

To achieve a low GI diet, try to choose one low GI food at each meal. The following tables are a good guide for choosing lower GI foods. You do not have to avoid all high GI foods, but try to eat them with a low or moderate GI food whenever possible. This will bring down the average GI of the meal.

 

(Table below correct at time of publishing as per GI Database www.glycaemicindex.com)

Low GI	Moderate GI	High GI
Breads
Mixed grain breads Pumpernickle bread Soy and linseed bread Some fruit loaf / Raisin breads	Wholemeal bread Crumpets Pita bread Light rye	White bread Bagels/Baguettes Dark rye (swiss variety) English muffin (white)
Cereal Foods
Pearl barley Fresh rice noodles Pasta	Basmati™ and Doongara™ rice Cous Cous Semolina Gnocchi Dried rice noodles	Calrose™ and Jasmine ™rice Tapioca Rice Cakes
Breakfast Cereals
Rolled oats / Porridge Guardian™ All Bran™ Rice/oat/barley bran Special K™ (Australian)	Vita Brits™/ Weetbix™ Shredded wheat™ Untoasted muesli Mini wheats™ (whole wheat) Sustain™ Just Right™ Healthwise™ for bowel health	Rice bubbles™ Sultana Bran™ Corn Flakes™ Puffed wheat™ Coco pops™
Biscuits and Crackers
Oatmeal	Arrowroot™ biscuits Digestives™ Ryvita™	Rice Cakes Water crackers Saos™ Corn Thins Kavli
Fruit
Apples Cherries Grapefruit Grapes Oranges Peaches Pears Kiwifruit Plums Dried apricots	Paw paw Rockmelon Sultanas Raisins Apricots Pineapple Mango	Watermelon
Milk and Dairy Foods
Reduced/low fat milk Soy milk Low fat yoghurt Low fat ice cream Custard	Vitari™
Vegetables
Sweet potato Sweet corn Legumes e.g. Baked beans, chick peas, split peas, kidney beans, lentils, soya beans	Potato (boiled / baked)	Instant potato Broad beans Potato (mashed) French fries New potato (Australian)