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Nutrition
Glycemic Index
In the option strand, Contemporary Food Issues: Nutrition you will investigate contemporary food issues. The glycemic index of food has been used by people with diabetes to monitor their diet, however it is increasingly being used as a way to help people who are overweight, to lose weight. This tutorial examines what the glycemic index of food is and how it can be used to improve the health status of Australians.
Outcomes
This material addresses aspects of the following syllabus outcome:
H3.2 The student investigates contemporary food issues.
Source: Board of Studies NSW, Stage 6 Food Technology Syllabus, Preliminary and HSC Courses (1999)
What is the glycemic index of food?
The glycemic index (GI) of food is a
ranking of foods based on their immediate effect on blood glucose (blood
sugar) levels. Carbohydrate foods that breakdown quickly during digestion
have the highest glycemic indexes. Their blood sugar response is fast and
high. Carbohydrates that breakdown slowly, releasing glucose gradually into
the blood stream, have low glycemic indexes.
Source: http://www.glycemicindex.com/ 
The GI is especially useful to people with diabetes who want to plan their diets to minimise the incidence of high blood sugar. Using the GI helps keep blood sugar levels under control. While it is useful for people with diabetes, it is also useful for athletes and people who are overweight.
People with diabetes who
keep their blood sugar under tight control are more likely to
avoid the complications of the disease. The basics of a good diet for people
with diabetes and everyone in general is:
- regular exercise
- low intake of saturated or partially hydrogenated oils
- high fibre diet.
But not all carbohydrates behave in the same way. Some break down quickly in the intestine which causes blood sugar levels to rise rapidly. These carbohydrates have a high glycemic index and should be avoided by people with diabetes or those trying to lose weight.
- Rank order the following foods in
terms of highest glycemic index reading to lowest. Which foods would be
better for someone trying to monitor their weight or diabetes?
Donut 108 Soy milk 43 Bürgen Soy Lin bread 27 Porridge (oatmeal) 70 Sustain breakfast cereal 97 Barley, pearled 36 Rice, Sunbrown Quick 114
The University of Sydney Australian GI Database can be used to find the GI of certain foods or to find
foods with certain GIs. You may find that different GIs have different
scores for foods, this is because the index is either measured against
white bread or glucose.
- What is the significance of glycemic index?
- Plan a day's meals using four low GI foods.
The GI Symbol Program
The GI symbol will
soon appear on a variety of foods tested for GI. The tests must be carried
out by an accredited testing laboratory. The GI number will appear near the
nutrition panel, with a brief explanation.
The foods must also meet strict guidelines for total and saturated fat and sodium and nutrient density. In addition, food products must contain at least 10 g of carbohydrate per serve and be a source of dietary fibre.
Why put the Glycemic Index on food labels?
Up until now, people have had to rely on
published lists of the glycemic index of foods to help them decide which
carbohydrate foods to eat. By placing the glycemic index directly on the
label of foods, consumers will be better able to follow national and
international guidelines. Adapted from http://www.glycemicindex.com/
Diabetes
If you choose to investigate the health of people who have diabetes or are prone to developing diabetes the following web site may be useful:
http://www.diabetesnsw.com.au/
- Why are camps arranged for children and teens with diabetes?
- Outline the latest findings of the AusDiab (Australian Obestity and Lifestyle) Study. What do you think are the implications of these results for the health of Australians?
- Why do you think knowledge of GI would help all Australians achieve a healthy diet?
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