Glycaemic Index (GI)

 

Carbohydrate foods (i.e. breads, cereals, fruit, starchy vegetables, legumes, milk and yoghurt) are primarily broken down to glucose, which provides energy for our bodies. The Glycemic Index (GI) indicates how quickly different carbohydrate foods raise our blood glucose levels, ranking foods numerically, from 0 to 100.

 

Carbohydrate foods that are readily digested and cause blood glucose levels to rise quickly are called high GI foods (they have a value greater than or equal to 70). Foods that are broken down slowly and provide a more sustained supply of glucose for energy are called low GI foods (these have a value less than or equal to 55).

 

WHY IS GI IMPORTANT?

Foods with a lower GI break down more slowly during digestion, giving a slower and more even rise in blood glucose levels, helping sustain energy levels for longer.

Low GI foods are more likely to fill you up and keep you satisfied for longer. This can reduce the desire to snack between meals.

Foods with a higher GI break down the fastest during digestion. High GI foods are useful for some groups of people, such as athletes, who need a fast supply of glucose to fuel their muscles during the competition.


WHAT ARE THE GI LEVELS OF DIFFERENT FOODS?

Food: Low GI (GI<55) Medium GI(GI>55 and<70) High GI (GI >70)
Bread Dense grain and some high quality multigrain breads, quality sourdough bread Pita bread, rye bread, lower GI white bread White/wholemeal bread, crumpets, English muffins, pikelets, plain scones
Grains/Pasta Pasta, Barley, cracked wheat, noodles, Doongara rice Basmati rice Calrose and Jasmine rice, rice cakes, water crackers, puffed crisp bread
Cereal Natural muesli, coarse rolled oats, some less refined breakfast cereals Low fibre cereals like rice crisp cereal, corn flakes
Vegetables Corn, carrots, lentils, chick peas, kidney beans, baked beans and parsnip, Carisma potatoes Beetroot, sweet potato Potato (including baked, mashed, steamed & boiled) and swede
Fruit Apples, apricots, dates, oranges, mandarins, kiwifruit, grapes, strawberries, mangoes, pears, peaches, apricots, nectarines and bananas Pineapple, rockmelon Watermelon
Dairy Milk, yogurt, ice cream, custard

THINK LOW GI FOR GOOD HEALTH

Studies have shown that following a low GI diet may have benefits for improved management of blood glucose levels, weight control and reduce the risk of a number of health problems such as Diabetes.

People who have difficulties managing their blood glucose levels may benefit from incorporating low GI foods into their diet as they provide a gradual rise in blood glucose levels. This slow release of glucose into the bloodstream may also assist with controlling appetite and therefore weight. The reduction in insulin secretion that occurs with a low GI diet may also have benefits for reducing risk factors for metabolic syndrome and glucose intolerance.

ARE LOW GI FOODS THE BEST CHOICE?

Research has shown that choosing a diet that includes lower glycemic index (GI) carbohydrates, as well as reducing saturated fats and increasing fruit, vegetables and fibre can help achieve good health. Therefore your food choices should not be solely based on their GI value alone. Eating a wide variety of foods from the core food groups, and including some lower GI foods, is the key to a balanced and enjoyable way of eating.

HOW TO LOWER THE GI OF YOUR DIET

Getting the benefits from low GI eating doesn't need to be complicated. You don't need to avoid high GI foods, simply swap some of your carbohydrate foods to lower GI choices. Lower the GI of your diet by include one low GI food at each meal – for example, adding a low GI food like a tub of fruit yogurt to a higher GI food like watermelon will help to reduce the overall GI of the meal. It is important to remember that portion size counts, so just because it's low GI, it doesn't mean you should eat more! In fact you may find you eat less as low GI foods can keep you feeling full for longer.

SHOPPING – THE LOW GI WAY

Some food products have the GI value listed on the label. Those that have been tested at an Accredited Laboratory and meet stringent nutrition criteria so that they are all-round healthy choices carry the GI Symbol – go to www.gisymbol.com for further details. The GI of many other foods has been tested and are listed in the GI tables of the "New Glucose Revolution books" and on the website www.glycemicindex.com.

This fact sheet contains general information. Please consult your healthcare professional for specific advice for your personal situation.

If you would like current information about our products please visit www.nestle.co.nz/brands or call our Consumer Services Department during business hours on 0800 830 840.


REFERENCES

Glycaemic Index website accessed Apr 2011, www.glycemicindex.com

Health Insite Glycaemic Index Dec 2010

Better Health Channel accessed Apr 2010, Carbohydrates and the glycaemic index, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/carbohydrates_and_the_glycaemic_index

Diabetes Australia Glycaemic Index accessed Apr 2011 http://www.diabetesaustralia.com.au/Living-with-Diabetes/Eating-Well/Glycaemic-Index-GI/