1 June 2006

GI News—June 2006


In This Issue:

  • Food for Thought
    —Let's Do Lunch
  • GI News Briefs
    —Test Is Best
    —A Public Health Time Bomb
    —Teenagers Make Healthy Changes Given the Chance
  • GI Values Updates
    —No Time to Cook? Nestle LEAN Cuisine; Sanitarium Lunch Today
    —What’s the GI of …? A Step-by-Step Guide to the GI Database on www.glycemicindex.com
  • Low GI Food of the Month
    —The Antioxidant-rich Orange
  • Low GI Recipe of the Month
    —Citrus Salad with White Wine and Thyme Syrup
  • Success Stories
    —Sue Drops a Dress Size
  • What's New?
    —Peter Howard’s Delicious Living
    —Revised US edition of What Makes My Blood Glucose Go Up and Down?
  • Feedback—Your FAQs Answered
    1. I've read that while fats slow down the body's response to high GI foods, the body still sees the same level of glucose response from the food, just over a considerably longer period of time (which is perhaps not accounted for when doing GI testing). Is this true?
    2. What about a glossary? I'm familiar with glycemic index, glycemic load, and a few other ‘normal’ GI terms, but when I start reading terms like ‘glycemic response’ or ‘glycemic impact’ I begin to wonder whether I know anything at all.
    3. Are NutraSweet or Splenda considered as being low GI?
    4. Why is there no information about stevia?
    5. I read that people just trying to lose weight or eat more healthily should use GL, but people with insulin resistance (like me) should use GI. Is this true?

june quote

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GI News Editor: Philippa Sandall
Web Design and Management: Scott Dickinson

Food for Thought

Let's Do Lunch
While most people agree that eating a healthy lunch is important, one in three skip it at least once a week, and one in 10 rarely or never have it according to a recent ACNeilsen Omnibus poll of 1,400 Australians. ‘Too busy’ is the main catch-cry of lunch-skippers. ‘We don’t have time to go out or make something to eat’ said 43% of the skippers; while another one in ten said they had too many personal chores to do to fit food into their break. A further 20% of respondents simply said that they weren’t hungry at lunchtime. Dietitian Cathy McDonald of the Sanitarium Health Food Company who commissioned the poll said the research shows that many people are clearly not making lunch – and their health – a priority. ‘Eating lunch assists in ensuring you get all the vitamins, minerals and other nutrients you need each day. Taking time out can also help improve concentration levels, give you time for building relationships and even increasing fitness levels if you do some exercise during your break.’

She said that the poll also confirms that many people grab a bite to eat rather than ‘doing’ lunch. One in three people have a 20–30 minute lunch break; a further one in five take less than 20 minutes; 5% don’t stop for lunch at all; and one in five eat at their desk or on the run. ‘This might seem great for productivity, but a rushed lunch-time means you are missing out on important health benefits both from a nutritional, stress management and a relaxation perspective,’ she said. ‘Taking time to eat lunch is critical to maintaining health, controlling weight, boosting energy and concentration levels and simply feeling better overall.’ The team at GI News wholeheartedly agrees! In fact it can be more productive to take a break from office stresses, to ‘do lunch’ with friends/co-workers and get back to your desk with a fresh perspective on the job in hand.

Cathy McDonald

Check Out the GI Group’s ‘Let’s Do Lunch’ Basics
Lunch doesn’t need to be a big meal. But you need to choose a food from each group – carbs, protein and fruit and vegetables. Here’s how:
Start with a low GI carb such as wholegrain or sourdough bread, pasta, noodles, sweet corn, legumes (pulses).
Add some protein like fresh or canned salmon or tuna, lean meat, sliced chicken or turkey, reduced fat cheese or an egg. Legumes (pulses) also can count as protein.
Plus vegetables or salad to help fill you up. A large salad made with a variety of vegetables would be ideal.
Round off with fruit. If you opt for juice, remember, about ¾ cup (200 ml) is one serving. So if you are thirsty, make it a spritzer and top it up with sparkling mineral water.

Try these simple suggestions for a cup of soup, a sandwich or filled roll or a salad bowl you can make yourself or pick up from the local deli.

  • Minestrone soup made with plenty of beans and vegetables and served with a little grated parmesan and a grainy roll.
  • Salad sandwich made with mixed grain, soy and linseed or sourdough bread (or a roll) and filled with lean turkey slices, tomato, sprouts, grated carrot, finely sliced onion rings and mixed salad greens. Try a smear of avocado on the bread instead of margarine and add a dollop of cranberry jelly.
  • Chilli salmon salad: In a bowl, combine 1 small can red salmon (drained and flaked) with ½ punnet cherry tomatoes, slices of red onion, red and yellow capsicum strips and mixed salad and baby spinach leaves. Toss in a chilli dressing made from olive oil, lemon juice and minced chilli and serve with a grainy or sourdough bread roll.
– Source: Low GI Eating Made Easy

Photo: Ian Hofstetter, The Low GI Diet Cookbook

GI News Briefs

Test is Best
The GI was introduced to rank the glycemic nature of the carbohydrate in individual foods. The purpose was to exchange one carbohydrate source with another in mixed meals or snacks. People often ask about the effect of extra protein and fat in the food on GI and blood glucose response. Eaten alone, protein and fat have little effect on blood glucose levels, but that’s not to say they won’t affect your blood glucose response when combined with a carb-rich food. This is because protein and fat both tend to delay stomach emptying, thereby slowing the rate at which carbohydrate can be digested and absorbed. So a high fat meal will have a lower glycemic effect than a low fat meal even if they both contain the same amount and type of carbohydrate. As most GI testing to date has been with carb-rich single foods, there’s been some uncertainty and controversy about the best way to apply it to mixed meals and whether it can be predicted using GI tables.

Prof Jeya Henry and colleagues from Oxford Brookes University set out to investigate the impact of protein and fat toppings on the glycemic response to three popular carb foods (potato, pasta and white toast). Writing in the European Journal of Clinical Nutrition the researchers report that toppings of cheddar cheese, chilli con carne, baked beans or tuna on baked potato, pasta and toast had a consistent lowering effect on the GI. The high fat cheese topping (42 g fat, most of it saturated) produced the greatest reduction in the glycemic response, especially when combined with the potato which, when eaten alone, had the highest GI value of the three staples (from GI 93 down to GI 39). In concluding the authors say that the ‘findings highlight the importance of investigating the GI of composite meals’. (The study was sponsored by the British Potato Council.)
European Journal of Clinical Nutrition 2006 Jan 25

GI Group: As we said in January GI News, the common cut-offs for high (GI 70) and low GI (55 or lower) were based on the scatter of GI values among single foods. If the future holds more testing of the glycemic impact of mixed meals, then the cut-offs may need to be redefined, taking into account the observed range. More importantly, a meal’s GI value doesn’t make it good or bad for you. You need to base your food choices on the overall nutritional content along with the amount of saturated fat, salt, fibre and of course, GI value. We have found that people who simply substitute a low GI food for a high one in their everyday meals and snacks (especially with their choice of breads, breakfast cereals, starchy vegetables) reduce the overall GI of their diet, gain better blood glucose control and lose weight.

See ‘Feedback’ for more on fats, spikes and glycemic response.

A Public Health Time Bomb
‘The obstacles are enormous in contemporary society where daily physical activity opportunities are limited for some youngsters, entertainment is sedentary, and high-fat, high-energy foods are cheap, ubiquitous, convenient and heavily promoted’ writes Dr Arlan L. Rosenbloom in the May issue of Archives of Pediatrics and Adolescent Medicine. He was responding to Glen Duncan’s data published in the same issue suggesting that the US faces a public health time bomb – around 39,000 teenagers aged between 12 and 19 may have type 2 diabetes and 2.8 million impaired fasting glucose levels. Duncan put some realistic figures on the potential size of the problem in the US using data from the National Health and Nutrition Examination Survey (1999–2002).

The estimates have important implications for public health because of the high rate of conversion from impaired glucose fasting level to type 2 diabetes in adults and the increased risk of cardiovascular disease in individuals with type 2 diabetes. It’s unknown, says Rosenbloom ‘whether weight loss will prevent or slow the progression to diabetes in this age group.’
Archives of Pediatrics and Adolescent Medicine Vol 160 May 2006

Teenagers Make Healthy Changes Given the Chance
Simply replacing sugar-sweetened beverages with non-caloric drinks in the home (where young people get most of their food and beverages) helped a group of teens cut consumption of high calorie drinks by more than 80%. They also shed pounds according to a randomised pilot study reported in the March issue of Pediatrics.

Consumption of sugar-sweetened drinks – sodas, sports drinks, juice drinks, iced teas, lemonades and punches – has surged in recent decades, in step with the surge in childhood obesity. So is there a connection? Researchers from Children's Hospital Boston carried out a controlled trial led by Cara Ebbeling, PhD, and David Ludwig, MD, PhD, to test the effect of decreasing sugar-sweetened beverages on body weight. ‘We opted to study one simple, potentially high-impact behaviour, and made it easy for adolescents to replace sugary drinks with non-caloric beverages in the home’ says Ebbeling.


They enrolled 103 children aged 13 to 18 through a Boston area high school. The teens were offered a $100 mall gift certificate if they stuck with the six-month study, and they all did. Half the group, received weekly deliveries of non-caloric beverages of their own choosing – bottled waters and artificially sweetened drinks. They were instructed on how to avoid sugar-sweetened beverages and given tips on choosing non-caloric drinks outside the home. Prompts included monthly phone calls and refrigerator magnets (‘Think Before You Drink’). The rest of the teens, serving as a control group, continued with their usual eating and drinking patterns. At the end of six months, the beverage delivery group had an 82% reduction in consumption of sugary drinks, while sugary drink intake in the control group remained unchanged.

The heavier the teen was initially, the stronger the effect on body weight. Among the heaviest one-third of teens, there was a marked decrease in body mass index (BMI) in the beverage-delivery group, and a slight increase in the control group – a group-to-group difference of almost 1 pound per month. Other factors affecting obesity – physical activity levels and television viewing – did not change in either group.
Pediatrics, March 2006

Corollary: Stopping School Soda Sales – Taking a Step in the Right Direction
Cadbury Schweppes PLC, Coca-Cola Co. and PepsiCo Inc have agreed to halt nearly all sales of sodas to US public schools (vending machines and cafeterias) agreeing to sell only water, unsweetened juice and low-fat milks to elementary and middle schools. Diet sodas would be sold only to high schools. The agreement should cover around 87% of the public and private school drink market. The Alliance for a Healthier Generation, a collaboration between the William Clinton Foundation and the American Heart Association, helped broker the deal.


Sugary soft drinks will also be banned from school canteens and vending machines in Australia from 2007. Ian Caterson, the Boden Professor of Nutrition at Sydney University said banning the soft drinks would help get the message across to parents that they were bad for children.

GI Symposium
Carbohydrates, Glycemic Index and Health: The State of the Art
When: 2 September 2006
Where: Powerhouse Museum, Ultimo, Sydney, Australia
Convenor Professor Jennie Brand-Miller, University of Sydney
Sponsor The University of Sydney Nutrition Research Foundation

For more information or to register, contact:
Elisabeth Eaton
GI Symposium Secretariat
PO Box 949, Kent Town SA 5071, Australia
Phone +618 8363 1307
Fax +618 8363 1604
Email FI2006@fcconventions.com.au


  • Professor Jennie Brand-Miller, University of Sydney, Australia
    ‘Overview of carbohydrates, GI and health, strengths and weaknesses of the GI concept’
  • Associate Professor Frank Hu, Harvard University, USA
    ‘Saturated fat or refined carbohydrates: which is the worse villain for heart disease?’
  • Dr Anette Buyken, Forschungsinstitut für Kinderernährung, Germany
    ‘The European experience of using GI – potential pitfalls’
  • Dr Emma Stevenson (or Clyde Williams), Nottingham University, UK
    ‘GI, exercise and fuel partitioning’
  • Ian Barclay, NSW, Australia
    Title to be confirmed
  • Kate Marsh, NSW, Australia
    ‘Putting the GI into good practice’
Dietary Study for Women with PCOS
The University of Sydney is conducting a dietary study for women with PCOS. If you live in Sydney, Australia, are aged 18–40 with PCOS and are not taking the pill or trying to conceive, contact pcosdietstudy@nnd.com.au for more details.

GI Values Update

No Time to Cook?
The home meal replacement market is here to stay. It’s a trend, not a fad – and it can provide a healthier option than a takeaway meal for time-pressed and kitchen-shy consumers who want to be able to open the fridge (or freezer) door, take their pick, heat and eat. There’s no question it’s handy. But with a worldwide obesity boom, how healthy is it? Here are six GI tested, single serving mixed meals available in Australian supermarkets. They were formulated by the manufacturers to be nutritionally balanced. The LEAN Cuisine meals also meet the GI Symbol program’s strict nutritional criteria regarding fat, saturated fat and sodium. Pre-portioned meals like these can help you avoid over-eating (if you stop at one). Just remember to sit down at the table while you eat and eat slowly – it takes 20 minutes before your stomach tells your brain that you're full. Toss a simple salad together for starters and finish with a piece of fruit to help you get your seven servings of fruit and veggies a day.

lean cuisine

LEAN Cuisine Wholegrain Goodness range (Nestlé)
‘These low GI meals were specifically developed by Nestlé to meet consumer requests for healthy, sustaining heat-and-eat meals that would reduce their afternoon snacking and night-time cravings,’ says Penny Small, Manager Corporate Nutrition, Nestlé Australia Limited. ‘Initial sales have exceeded expectations,’ she says ‘which all goes to show that given a real choice, time-poor consumers will take the healthy option when it’s offered.’

GI symbol
International GI symbol

GI tested at Sydney University’s Glycemic Index Research Service (www.glycemicindex.com), the LEAN Cuisine meals carry the international GI symbol, which gives consumers a credible, independent signpost to healthier food choices. For more information on the Glycemic Index Symbol Program’s nutritional requirements, go to www.gisymbol.com and select ‘industry information’ from the menu then ‘program eligibility’ and finally ‘nutrient requirements’.

Burmese Vegetable Curry & Rice GI 50
Chicken Pomodoro GI 47
Honey Soy Beef GI 53

honey soy

Sanitarium Lunch Today
These lunches/light meals were developed by Sanitarium to be 98% fat free and to include as many whole foods as possible. The Sweet Vegetable Risotto for example is 63% veggies and the Fajita 55% veggies plus 9% legumes. They were GI tested at Sanitarium Development and Innovation. (GI Group note: for the purposes of GI testing, the use of small glucometers is not ideal, as demonstrated by Valangi et al 2005).

Mediterranean Pasta GI 49
Sweet Vegetable Risotto GI 59
Mexican Fajita GI 52


What’s the GI of …? A Step-by-Step Guide to the GI Database on www.glycemicindex.com
Use the database to find the GI value of your favourite carbohydrate foods that have been tested over the past 25 years from all around the world. You can also check the glycemic load (GL) and grams of carbohydrate per serve. If you want to dig a little deeper, you can see where and when the food was tested and whether the test subjects were healthy or had diabetes. Although our database is the most comprehensive GI database resource on the web, we don’t have the GI values of every carbohydrate food tested. Sometimes food companies prefer not to publish the GI of their products, and sometimes they don’t want their foods tested at all.

Step 1
Go to www.glycemicindex.com and click on the GI Database link in the left-hand menu.


Step 2
To search for ‘beans’ for example, insert ‘beans’ in the ‘Name of the Food’ box and click search.


Step 3
To refine your search, use the less than (<) and greater than (>) symbols, to tell the database to show you only foods containing beans with a GI less than 55 and a GL greater than 20. Use the drop-down menu on the far right, to tell the database to sort the results by the GI and in ascending order.



Step 4
Now click on the actual food name (the text will change colour) and the following page appears.


The GI of the kidney beans was calculated using glucose as the standard. The serve (in grams) refers to the nominal serving size. This value is then used to calculate the GL value for each product. For example:

Red Kidney Beans
Serve (g): 150 g
CHO/serve (g): 60.3
GI: 51
GL = 31

In this case the test period was the standard 2 hours where a total of 9 finger-prick blood samples were taken in 10 subjects over that period (this includes 3 fasting samples). The subjects were ‘normal’ which means they were healthy volunteers. In some tests, ‘Type 2’ refers to testing in people with type 2 diabetes. Finally, the reference shows where the food was tested and in which journal the results were published if applicable.

Low GI Food of the Month

The Antioxidant-rich Orange
One orange (GI 42) provides you with your whole day’s vitamin C requirement. But that’s not all. This fruit is also rich in anti-oxidants and a good source of folate and potassium. Much of the sugar in an orange is sucrose, a ‘double’ sugar made up of glucose and fructose. When digested, only the glucose molecules have an impact on your blood glucose levels. This and the high acid content account for the low GI. There are many varieties available these days to help you enjoy eating a juicy orange year round. The main ones are jaffa (generally available year round), navel (autumn/fall, winter and spring) and valencia (spring and summer). But try something different. There are many other varieties worth keeping an eye out for. Blood oranges (winter through to early spring) for example are popular in Europe, particularly Mediterranean areas such as Spain and southern Italy where they grow prolifically. This variety, unusually for citrus fruit, contains anthocyanin, the blue/red pigment found in berries, red capsicum (pepper) and eggplant. Anthocyanin functions as an anti-oxidant, minimising the damage to cell membranes that occurs with aging.

Food: Lynne Mullins; Photo: Jennifer Soo

Here are some ideas for upping your orange intake:

  • Peel and enjoy the juicy segments with breakfast cereal, as a snack, or as an after-dinner palate cleanser.
  • Chop segments into fruit salads, toss into salads, add to soups or casseroles or to couscous; slice oranges and add to fruit punch.
  • Carrot and orange make a great couple—enjoy them together in a soup or salad.
– Reprinted courtesy Low GI Eating Made Easy (published by Hodder in Australia and NZ, Hodder Mobius in the UK and Marlowe & Company in the US)

Low GI Recipe of the Month

This fruity finish comes from Australian food writer Lynne Mullins who regularly contributes to Good Living and Sunday Life, reviews for the SMH Good Food Guide has published two books: Noodles to Pasta and Relish and currently presents fresh produce segments on radio 2UE and Channel Nine’s ‘Mornings with Kerri-Anne’.

Lynne Mullins

Citrus Salad with White Wine and Thyme Syrup
Ring the changes with the seasons with this dish. If navel oranges are all that’s available, it’s still delicious. The recipe is sweetened with pure floral honey (yellow box). If you prefer, sweeten to taste with an alternative sweetener that’s suitable for cooking.

Serves 4

1 blood orange
1 ruby orange
1 navel orange
2 black or green figs, halved
low fat yoghurt, to serve

White wine and thyme syrup
1/2 cup (125 ml/4 fl oz) fruity white wine, such as riesling
3 tablespoons pure floral honey (or to taste)
thinly peeled piece of lemon rind
1/2 cup (125 ml/4 fl oz) water
2 teaspoons fresh thyme leaves

To make the wine and thyme syrup, place wine, honey, lemon rind and water in a saucepan and stir over low heat until honey has dissolved into the mixture, then bring just to the boil, reduce heat and simmer over medium heat for 8–10 minutes or until syrupy. Discard rind, stir in thyme and cool.

Using a small knife, cut rind and pith from the oranges, then cut fruit into wedges and place in a large bowl with fig halves. Pour wine syrup over and toss gently to combine. Divide salad among bowls and serve immediately topped with yoghurt.

Per serving (with 1 tablespoon of low fat yoghurt)
Energy: 637 kilojoules/152 calories, protein: 2.8 g, fat: 0.2 g, carbohydrate 29.5 g, fibre 2.7 g

Food: Lynne Mullins; Photo: Jennifer Soo

Your Success Stories

Sue Drops a Dress Size
‘Having tried countless diets over the years to lose excess weight, I embarked on a low GI diet after Christmas 2005. Always a ‘foodie’, I not only enjoy nice food but I love to cook. My problem was portion control and my sweet tooth. I decided that low GI seemed a sensible route to continue to enjoy good food, but some re-education was necessary. I desperately wanted to drop several dress sizes and my determination was strong. That’s why I decided against the traditional slimming club (many of which I had tried in the past which only served to make me food obsessed).

I invested in several low GI cookbooks instead to ring the changes and to avoid meal-time boredom setting in, and I enrolled at my local gym. Meal times were interesting and plentiful and I honestly never felt hungry. The first couple of weeks I missed puddings and chocolate but soon kicked the sugar cravings – I now reward myself with an occasional square of dark chocolate and savour and enjoy it. I increased my activity levels steadily. I take a brisk daily walk for 20 minutes or so and I tried various gym classes until I found two which I love and look forward to immensely. No obsessive calorie counting has meant this new regime is not a ‘slimming diet’ but has become my new way of life, my family and I are all much healthier for it. I have lost 1 stone 10 lbs (24 pounds/11 kg) in 4 months with real ease and I am so much happier and more confident. Learning about low GI has changed my life!’

Send Us Your Success Story!
success story

Books, DVDs, Websites: What’s New?

Delicious Living
By Peter Howard, New Holland Publishers AUD$19.95

Peter Howard

Peter Howard is a well-known food and wine commentator. For many years his national television segments, regular radio interviews and articles in magazines and newspapers have kept Australian audiences informed of the latest trends. Two years ago, he was diagnosed with diabetes. ‘I know, like so many folk now, that we have a disease that will not go away, but can be controlled by diet, exercise and restraint or discipline’ he says in the introduction to this book. ‘I know many diabetics before me have faced and won this same dilemma. It is a difficult, private battle. We have to forgive ourselves for arriving at this stage and just get on with life … and our newfound lifestyle.’ Here’s a taste of the recipes he lives by … 99 per cent of the time. The book is endorsed by Diabetes Australia.

Spiced Yoghurt Pork Fillet and Pan-fried Pears
Preparation time 30 minutes
Cooking time 20 minutes
Serves 4

600 g (1 lb 5 oz) pork fillet cut into (4–5 cm/1¾–2 inches thick), all fat removed
150 ml (5 fl oz) no fat natural yoghurt
1 teaspoon smoked paprika
1 teaspoon fennel seeds, roughly crushed
1 teaspoon coriander powder
1/4 medium onion, finely chopped
1 tablespoon minced fresh oregano
2 teaspoon mustard seed oil
lemon flavoured cracked peppercorns
8 canned pear halves, well drained
120 g (4 oz) cooked silverbeet or spinach leaves

Preheat the oven to 180ºC (350ºF). In a small bowl, combine the yoghurt, paprika, fennel, coriander, onion and oregano and mix well.

Gently flatten the pork medallions by pounding them with the heel of your hand. Smear each piece of pork with the yoghurt mixture and leave to sit for 15–30 minutes, or longer if you have the time. Place the pork medallions on a baking tray and cook in the oven for 15 minutes or until firm. It is OK to leave your pork fillet pink. Heat the oil in a non-stick pan, sprinkle the pear halves with cracked pepper and pan fry to golden brown.

Pile equal amounts of cooked silverbeet on each plate, top with equal quantities of pork and 2 pear halves each.


Per serving:
1200 kJ/280 calories, 36 g protein, 6 g fat (1.6 g sat fat), 19 g carbohydrate,
low GI

What Makes My Blood Glucose Go Up and Down? revised edition published by Marlowe & Company is now available. We reviewed this in October 2005 GI News. Check the ‘Archive’ or use the Google Search facility to read the review.


Feedback—Your FAQs Answered

I've read that while fats slow down the body's response to high GI foods, the body still sees the same level of glucose response from the food, just over a considerably longer period of time (which is perhaps not accounted for when doing GI testing). Is this true?
No, this isn’t true. Fats do slow down digestion and reduce overall blood glucose levels, even if we continued testing beyond 2 hours. But you need the same amount of insulin, possibly more because excess fat intake makes you insulin resistant. The bottom line: choose a diet of 25–35% energy from fats. Good fats of course. We published a paper in 2004 on it in the American Society for Nutritional Sciences entitled: ‘The degree of fat saturation does not alter glycemic, insulinsemic or satiety responses to a starchy staple in healthy men’.

What about a glossary? I'm familiar with glycemic index, glycemic load, and a few other ‘normal’ GI terms, but when I start reading terms like ‘glycemic response’ or ‘glycemic impact’ I begin to wonder whether I know anything at all.
We try where possible to turn the science into everyday language, but sometimes terms are quite specific so a glossary is a great idea. We’ll start with the ‘GI terms’ you raise and keep building the glossary over the next few issues. When it’s completed, we’ll post it on the website as a ready reference.

Glucose When you eat carbohydrate foods such as bread, cereals and fruit, your body converts them to glucose (a monosaccharide sugar that’s present in most animal and plant tissues) during digestion. It is this glucose that is absorbed from the intestine and becomes the fuel that circulates in the bloodstream. As the level of blood glucose rises after you have eaten a meal, your pancreas gets the message to release insulin which then drives the glucose out of the blood and into the cells. Once inside the cells it is channelled into several pathways simultaneously – to be used as an immediate source of energy, converted into glycogen (a storage form of glucose) or into fat.

Blood glucose (blood sugar) is the amount of glucose in the blood stream. If you haven’t eaten in the past few hours (and you don’t have diabetes), your blood glucose level normally falls within the range of 3.5–6 mmol/L. If you eat, this will rise, but rarely above 10 mmol/L. The extent of the rise will vary depending on your glucose tolerance (your own physiological response) and the type of food you have just eaten. Although blood glucose levels will fluctuate over the course of the day, they will normally remain with this fairly narrow range. Keeping levels within the normal range is important for your health whether you have diabetes or not.

The test that measures your average blood glucose level over the past 2–3 months has a variety of names. It’s mostly described as HbA1c (hemoglobin A1c or glycated hemoglobin). It indicates the percentage of hemoglobin (the part of the red blood cell that carries oxygen to the cells and sometimes joins with glucose in the bloodstream) that is ‘glycated’. Glycated means has a glucose molecule riding on its back. This is proportional to the amount of glucose in the blood. The higher the level of HbA1c, the greater the risk of developing diabetic complications. People with diabetes should aim to keep their HbA1c at or less than 7%.

Glucagon Between meals your blood glucose levels will start to fall. As this happens, the pancreas releases the hormone glucagon into the blood. This hormone promotes the conversion of glycogen stored in the liver and muscles to glucose and raises your blood glucose level to keep it within the normal range.

Glycemia is the concentration of glucose in the blood. Hence the adjective, glycemic.

Glycemic Index (GI) Different carbohydrate foods can behave quite differently in your body. Some break down quickly during digestion and release glucose rapidly into the bloodstream; others break down gradually as you digest them and slowly trickle glucose into the blood stream. The glycemic index or GI, a relative ranking on a scale of 0 to 100, is how we describe this difference. After testing hundreds of carbohydrate foods around the world, scientists have found that foods with a low GI will have less effect on your blood glucose than foods with a high GI. High GI foods tend to cause spikes in your glucose levels whereas low GI foods tend to cause gentle rises. To make a fair comparison, all foods are compared with a reference food and tested following an internationally standardised method.

Glycemic Load (GL) How high your blood glucose actually rises and how long it remains high when you eat a meal containing carbohydrate depends on both the quality of the carbohydrate (its GI) and the quantity of carbohydrate in the meal. Researchers at Harvard University came up with a term to describe this: glycemic load. It is calculated by multiplying the GI of a food by the available carbohydrate content (carbohydrate minus fibre) in the serving (expressed in grams), divided by 100.
GL = GI/100 x available carbs per serving.

Glycemic potential A food or meal’s predicted blood glucose raising effect.

Glycemic response or glycemic impact describes the change or pattern of change in blood glucose after consuming a food or meal. Glucose responses can be fast or slow, short or prolonged. It is primarily determined by the food’s carbohydrate content. Other factors include how much food you eat, how much the food is processed and even how the food is prepared (for example, pasta that is cooked al dente has a slower glycemic response than pasta that is overcooked).

Glycogen is the name given to the glucose stores in the body. It can be readily broken down into glucose to maintain a normal blood glucose concentration. In an adult male, approximately two-thirds of the body’s glycogen is found in the muscles and one-third in the liver. The total stores of glycogen in the body are relatively small however, and will be exhausted in about 24 hours during fasting or starvation.

Hypoglycemia (also called an insulin reaction) occurs when a person’s blood glucose falls below normal levels – usually less than 4 mmol/L. People with diabetes know all about it. Hypoglycaemia is treated by consuming a carb-rich food such as a glucose tablet. It may also be treated with an injection of glucagon if the person is unconscious or unable to swallow. If you don’t have diabetes, but you have vague health problems ranging from tiredness to depression and think you may have hypoglycemia or someone tells you that you probably have ‘low blood sugar’, see your doctor and get a proper diagnosis. Hypoglycemia is far less common that once was thought in people who do not have diabetes.

Impaired glucose tolerance is sometimes called pre-diabetes or impaired fasting glucose. It is a condition in which blood glucose levels are higher than normal, but are not high enough for a diagnosis of diabetes. People with impaired glucose tolerance are at increased risk of developing diabetes, heart disease and stroke.

Insulin is a hormone produced by the pancreas that helps the body use glucose for energy. Although the body needs glucose, it doesn’t want it all in one hit, so it pumps out insulin to drive the glucose out of the blood and into the tissues. The pancreas should automatically produce the right amount of insulin to move glucose into the cells. People with type 2 diabetes do not always produce enough insulin. People with type 1 diabetes produce no insulin at all. When the body cannot make enough insulin, it has to be taken by injection or through use of an insulin pump. It can’t be taken by mouth because it will be broken down by the body’s digestive juices.

Insulin is not only involved in regulating blood glucose levels, it also plays a key part in determining whether we burn fat or carbohydrate to meet our energy needs – it switches muscle cells from fat burning to carb burning. For this reason lowering insulin levels is one of the secrets to life-long health.

Insulinemia simply means the presence of insulin in the blood; hyperinsulinemia is excessive amounts of insulin in the blood.

Insulin resistance When insulin levels are chronically raised, the cells that usually respond to insulin become resistant to its signals. The body then responds by secreting more and more insulin, a neverending vicious cycle that spells trouble on many fronts. Insulin resistance is at the root of diabetes, many forms of heart disease, and polycystic ovarian syndrome (PCOS).

Insulin sensitivity If you are insulin sensitive, your muscle and liver cells take up glucose rapidly without the need for a lot of insulin. Exercise keeps you insulin sensitive: so does a moderately high carbohydrate intake.

I have heard that the GI of sugar is 67 – is this true? Are NutraSweet or Splenda considered as being low GI?
In our online database, regular table sugar is listed under the scientific name ‘sucrose’, not as ‘sugar’. But point taken and we’ll see what we can do to get it cross referenced to make it easier to use the database. Sucrose has been tested on a number of occasions and has an average GI of 68. You can add a teaspoon of sugar to your tea or coffee without upsetting your blood glucose levels. For lower GI sweeteners, try a pure floral honey, 100% pure maple syrup, apple juice, grape nectar, or Sweet Cactus Farms agave nectar, or fructose sweeteners such as such as Sweetaddin® or Fruisana®.

Alan Barclay

Dietitian Alan Barclay of the GI Group says: ‘If you are trying to lose weight or reduce your insulin or oral hypoglycemic medications, alternative sweeteners can be handy. There are numerous brands, but essentially just two main types:

  • nutritive sweeteners
  • non-nutritive sweeteners
Nutritive sweeteners including sugars, sugar-alcohols, and oligosaccharides (medium-sized chains of glucose) are simply different types of carbohydrate with varying levels of sweetness. The sugar alcohols like sorbitol, mannitol and maltitol are generally not as sweet as table sugar, provide fewer kilojoules and have less of an impact on blood glucose levels. To overcome their lack of sweetness, food manufacturers usually combine them with non-nutritive sweeteners to help keep the kilojoule-count down and minimise the effect on blood glucose levels so check the ingredient listing on the food label.

Non-nutritive sweeteners (such as Equal®, Splenda®, NutraSweet® or saccharin) are all much sweeter than table sugar and have essentially no effect on your blood glucose levels because most are used in such small quantities and are either not absorbed into or metabolised by the body. Because they are only used in minute amounts, the number of kilojoules they provide is insignificant. The best non-nutritive sweeteners to cook with are Splenda®, saccharin and Neotame®, and to a lesser extent Equal Spoonful®. This is because the non-nutritive sweeteners made of protein molecules often break down when heated for long periods and lose their sweetness.’

Why is there no information about stevia?
Stevia (Stevia rebaudiana), native to South America, first came to the attention of the Western world in the 1800s, but remained relatively obscure until it was used as an alternative sweetener in the UK during the Second World War. It’s not widely available. The leaves of this semi-tropical herb of the aster family are around 30 times sweeter than cane sugar but with no kilojoules (calories). As a herb, they can be used fresh or dried. In the dried form less than 2 tablespoons of crushed leaves can replace a cup of sugar, although it's hard to be specific as actual sweetness can vary. Stevioside, its extract, is 250–300 times sweeter than sucrose and is not approved for use as a food in Australia but is listed as a 'therapeutic good' with the Therapeutic Goods Administration. You can buy the herb, stevia leaf powder, online from specialty spice merchants such as Herbies Spices (www.herbies.com.au). Herbie (Ian Hemphill) has a couple of hints for using stevia. He says: ‘use sparingly as there is a bitter aftertaste if too much is added to food. Because stevia does not have the same properties of sugar, it is not suitable as a sugar substitute when baking.’

Stevia plant

I read that people just trying to lose weight or eat more healthily should use GL, but people with insulin resistance (like me) should use GI. Is this true?
Our advice is to stick with the GI in all but a few instances. When you choose low GI carbs you’re invariably getting a healthy diet with an appropriate quantity and quality of carbohydrate. Portion size still counts, though. And this is where low GI foods are star performers – the foods with the lowest GI values also have the best fill-up factor. If you listen to your true appetite, you are far less likely to overeat when you are choosing low GI foods.

GL doesn’t distinguish between foods that are low carb or slow carb. Going with GL could mean you’re eating an unhealthy diet, low in carbs and full of the wrong sorts of foods. So the take home message is to use GI to identify the best carbohydrate choices and take care with portion size to limit the overall GL of your diet.

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