Food Fact: The Glycaemic Index

Download and print as a PDF (240kB pdf)

Carbohydrate

Food containing carbohydrate is an essential part of our diet. It provides us with our main source of energy, which is glucose. It is best to try to have similar amounts of carbohydrates from day to day, spreading the amount evenly over the day.

Foods that contain carbohydrate include:

• sugar (all types), e.g. glucose, fructose, dextrose, syrup, honey, etc.
• cereal based products, e.g. breakfast cereals.
• fruit and fruit juices.
• grains, e.g. pasta, rice, couscous.
• breads, all types.
• milk and milk based products, e.g. yoghurt, ice cream, fromage frais.
• pulses, e.g. peas, beans, lentils.
• potatoes.
• some vegetables, e.g. corn, peas.
• snack foods, e.g. crisps, buns, cakes, biscuits.
• confectionary, e.g. sweets and chocolates.
• pies and pastries.

What is the Glycaemic Index (GI)?

All carbohydrate is digested and absorbed into your blood stream as glucose. The
Glycaemic Index ranks carbohydrate foods, depending on how quickly they are digested and absorbed into your blood stream as glucose.

Carbohydrates which are quickly digested and absorbed into the blood stream have a high GI. This causes a rapid rise in blood glucose levels.

Carbohydrates which are digested and absorbed slowly have a low GI. This causes a more controlled and steady rise in blood glucose levels.

High GI = Raise blood glucose levels quickly
Low GI = Slow rise in blood glucose levels

What are the benefits of low GI Foods?

Meals based on low GI foods help you manage your blood glucose levels between meals. This will help with your diabetes control.

Low GI foods can also help you to control your appetite, by making you feel full for longer. This will help you to eat less and so assist you to maintain a healthy weight.

People on low GI diets have been found to have a lower incidence of heart disease and
improved cholesterol levels.

Putting this into practice

• eat regular meals.
• try to include low GI foods at every meal as they can slow the absorption of other foods.
• try to eat similar amounts of carbohydrate at each meal.
• if you do choose a high GI carbohydrate think about what you will eat it with, e.g. try tuna with a jacket potato or a low sugar yoghurt after a white bread sandwich.
• add plenty of vegetables / salad to meals/sandwiches, etc.
• avoid high fat foods such as chocolate and nuts as snacks, especially if you are trying to lose weight, as they may have a relatively low GI but do contain a lot of calories.

Please note: Remember portion sizes are important to consider too. Even foods with a low/ medium GI such as grapes, banana or pasta, can push your blood glucose levels up higher than usual if eaten in large amounts.

Breads

• Low: Granary, multigrain, rye bread
• Medium: wholemeal bread, white and wholemeal pitta bread, muffins, crumpets, malt loaf
• High: white bread, baguette

Biscuits

• Low: oatmeal biscuits
• Medium: Rich Tea, digestive, shortbread
• High: crackers, morning coffee, vanilla wafer

Cereals

• Low: Porridge, Special K, All Bran
• Medium: Shredded Wheat
• High: Sultana Bran, Rice Krispies, Cornflakes, sugary cereals, e.g. Coco Pops

Grains and pasta

• Low: Pasta, buckwheat, bulger wheat
• Medium: Basmati rice, couscous, quinoa
• High: Brown and white rice, rice cakes, crackers

Potato

• Low: sweet potato
• Medium: boiled potatoes, new potatoes
• High: French fries, instant potato, roasted potato, mashed potato, baked potato

Veg and pulses

• Low: peas, lentils, beans, e.g. baked, kidney, carrots, yam, tomato juice
• Medium: beetroot
• High: parsnips, broad beans, pop corn

Fruit

• Low: apples, pears, citrus fruits, kiwi, cherries, plums, grapes, dried pear, dried apricots, dried peaches, mango, prunes
• Medium: mixed dried fruit, fresh apricot, fruit juice, sultanas, banana raisins, dried figs
• High: dried dates, melons, jam and marmalade

Dairy

• Low: low fat milk, diet yogurt, ice cream, low-fat custard, Yakult Light, Vitasoy soya milk
• Medium: N/A
• High: Vitasoy calcium enriched rice milk

Miscellaneous

• Low: dark chocolate, peanuts, cashew nuts, tomato juice, marmalade with no added sugar
• Medium: honey, reduced sugar jams
• High: sugar, glucose tablets, soft drinks, sweets, eg: jelly beans, marmalade