Warwickshire Dietetic Service
The Glycaemic Index
What is the Glycaemic Index?
The Glycaemic Index (GI) is a ranking of foods based on their effect
on blood sugar (glucose) levels.
Carbohydrate containing foods are given a GI number (between 0
and 100) according to their effect on blood glucose levels. Glucose
is used as the baseline (GI 100) and other foods are measured
against this.
Foods with a low GI are broken down more slowly into glucose and
therefore the rise in blood glucose after eating them is slower.
Foods with a high GI are broken down quickly into glucose and
therefore produce a quicker rise in blood glucose. The table on
page 3 gives examples of high, medium and low GI foods.
Glycaemic Index
What are the benefits of slow acting carbohydrates?
Choosing slowly absorbed carbohydrates can help:
Keep your blood glucose levels stable.
Control your appetite by making you feel fuller for longer, with the result that you eat less helping
with weight loss.
Enhance energy and concentration levels.
Improve levels of ‘good’ (HDL) cholesterol.
Contribute towards a healthy diet which could help protect against heart disease, strokes,
cancer and other longer term health conditions.
Does anything else affect GI?
The following can affect the GI of a food:
Physical form of a food e.g. wholegrains and high fibre foods act as a physical barrier that slows
down the absorption of starchy carbohydrate. Mashing foods and juicing drinks can raise the GI.
Type of starch e.g. the starch in pasta, porridge and basmati rice is digested more slowly.
Type of fibre e.g. the fibres in oats, fruit, beans and lentils slow down the rate of digestion.
Processing and ripeness of fruit e.g. as bananas ripen they have a higher GI.
Cooking methods e.g. frying foods can lower the GI.
Fat and protein slow down the absorption of carbohydrate.
Are all low GI foods healthier choices?
No, not all low GI choices are healthier options. Fat slows down digestion and the absorption of
glucose e.g. chocolate and crisps have a medium GI but this is because of their high fat content and
they are not a healthier choice.
What is the Glycemic Load?
Glycemic load (GL) accounts for the amount of carbohydrate in a portion of food together with the GI
e.g. watermelon has high GI, but a low carbohydrate content and so it won’t push up blood glucose
levels very quickly unless large quantities are eaten. For this reason it is important not to focus
exclusively on GI and to think as well about the overall balance of the diet.
Can I get hold of a list of GI values for all foods?
There are books and websites that give a long list of GI values for many different foods. These lists
can have limitations.
The GI of a food only tells you how quickly or slowly it raises the blood glucose when the food is eaten
on its own. In practice, we usually eat a mixture of foods at meals. Cutting out all high GI foods is not
the answer, instead try to include some more low and moderate GI foods in your meal as well.
Page 2
Glycaemic Index
The table below gives the GI rating for some common foods:
Low GI Foods Moderate GI Foods Higher GI Foods
Breads Granary, multigrain, rye, Wholemeal bread White, brown bread
pumpernickel, wholegrain Pitta bread Gluten free bread
breads. Muffins (English) Baguette
Multigrain crackers Crumpet Bagel
Fruit loaf Croissant French stick
Oatcakes Ryvita Pretzels
Oatmeal crackers Water crackers
Chapatis Naan bread
Breakfast Porridge, Oatibix, Puffed and Shredded Cornflakes, Rice
cereals Unsweetened muesli, Wheat, Weetabix, Krispies, Cheerios,
All Bran, Sultana Bran, Branflakes Sugar Puffs, Coco pops
Special K Cereal bars
Potatoes, Sweet potato New potatoes in their skins Instant potato
pasta, rice Pasta Jacket potato
Noodles Mashed potato
Spaghetti Chips
Basmati rice White and brown rice
Jasmine rice
Grains, beans All pulses e.g. beans, Couscous, millet
and pulses lentils, chickpeas.
Hummus
Buckwheat, quinoa,
barley
Fruit and Apple, pear, citrus fruits, Dried fruit, mango, Watermelon,
vegetables plums, prunes, grapes, banana, melon, pineapple dates, parsnips,
berries, cherries, dried pumpkin, swede
apricots, salad,
vegetables
Milk and dairy Milk, cheese, Ice cream
foods Yoghurts, fromage frais,
custard
Sugary/snack Dark chocolate, plain Digestives, rich tea Sweets, doughnut, iced
foods popcorn, sponge cake, biscuits, crisps, rice cakes, cakes, wafers,
nuts sucrose, honey, glucose
jam
Drinks Sugar free squash Fruit juice Lucozade, cola,
lemonade and other full
sugar drinks
Ref: Manual of Dietetic Practice.4th Edition/ the glucose revolution/Diabetes Uk
Page 3
Glycaemic Index
Menu suggestions
Breakfast
Oat-based breakfast cereals such as porridge or unsweetened muesli
Granary or wholegrain toast with topping of choice
Lunch
Jacket potato and baked beans
Lentil based soups
A sandwich made with seeded or wholegrain bread
Pasta or basmati rice salad with low fat dressing
Evening meal
Try basmati rice, sweet potato, new potatoes or noodles with your meal
Include more vegetables/salad
Add beans, pulses (dhal), buckwheat, bulgur wheat and pearl barley to soups, casseroles and
mince dishes
Snacks (optional)
Yoghurt (choose plain or diet varieties)
Plain popcorn
Oat cakes
Rye bread and fruit loaf
Fruit
Nuts and seeds
The above information is based on Diabetes UK recommendations.
Diabetes UK Central Office
Macleod House,
10 Parkway, London NW1 7AA
Tel 020 7424 1000
Fax 020 7424 1001
Email info@diabetes.org.uk
http://www.diabetes.org.uk
Page 4
Equality Statement
At South Warwickshire NHS Foundation Trust we are fully committed to equality and diversity,
both as an employer and as a service provider. We have a policy statement in our Equality
Strategy that clearly outlines our commitment to equality for service users, patients and staff:
You and your family have the right to be treated fairly and be routinely involved in decisions
about your treatment and care. You can expect to be treated with dignity and respect. You will
not be discriminated against on any grounds including age, disability, gender reassignment,
marriage and civil partnership, pregnancy and maternity, race, religion or belief, sex or sexual
orientation.
You have a responsibility to treat other service users, patients and our staff with dignity and
respect
Our information for patients can also be made available in other languages, Braille, audio tape,
disc or in large print.
PALS
We offer a Patient Advice Liaison Service (PALS). This is a confidential service for families to
help with any questions or concerns about local health services.
You can contact the service by the direct telephone line on 01926 600 054 by email:
Pals@swft.nhs.uk or by calling in person to the PALS Office which is located in the Lakin Road
Entrance to the hospital.
If you have any queries about your diet, please contact us on 01926 600818,
selecting option 3.
Dietetic Department Dietetic Department
George Eliot Hospital Warwick Hospital
Nuneaton Warwick
Author Registered Dietitian
Department Dietetics
Contact no 01926 600818
Published April 2016
Review April 2019
Version no 1
SWH No 01429
