1 July 2013

GI News—July 2013


  • Our clockwork body - why when we eat matters for our health; 
  • New low GI gluten-free foods on supermarket shelves; 
  • Going bananas for good health;  
  • Better-for-you family baking: Banana Bread and flourless Applesauce Oat Bran Muffins with Pinoli;  
  • Understanding the difference between GI, GL and glycemic response;  
  • The real health benefits of low GI/GL diets.   
GI News 
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Food for Thought

Baking boom. 
Home baking is on the rise as many people rediscover the joy of baking better-for-you desserts and snacks packed with wholesome ingredients you can ‘picture in their raw state or growing in nature’ (Michael Pollan’s Food Rule Number 14) along with the pleasure that a home-baked cake, muffin or cookie brings family and friends.

‘Baking brings love alive,’ says food writer Kate McGhie. ‘From the day I first licked the mixing bowl I was hooked,’ she confesses. ‘Growing up in the country, I was immersed in baking for an early age. Plonked as a tot on the large kitchen table I absorbed the knowledge of my Mother and her Mother. There was no holding back. I wanted to bake. Baking is different from cooking. You cook for yourself but with baking you are making something for other people. Before long I realised that the torch of love is lit in the kitchen. It is called baking.’

Anneka Manning
Anneka Manning's Nutty Oat Biscuits from The Low GI Family Cookbook is one of those recipes where there's lots to do for children who love to help with baking

Don an apron. You don’t have to deny yourself and those you love the pleasure of home baking eating the low GI way. Quite the opposite. Here at GI News we know that enjoying something sweet is instinctual and hard to ignore. After all, honey was a significant part of hunter-gatherer diets and a lot more concentrated back then as a source of sugar than most of the sweet foods we eat today. However, we do recommend you stick (most of the time) with better-for-you baking for desserts and snacks and keep seriously sugary and creamy indulgences for ever-so-very occasional treats.

Here are our tips for great-tasting, better-for-you, lower GI baking the whole family will love. First of all, downsize portions (a little goes a long way) – small pieces for cakes, bars, and slices; little bites for cookies and biscuits; and mini or medium tins for muffins and cupcakes. And when you pull out your favourite cookbooks, opt for recipes that:

  • Make the most of wholegrain ingredients such as wholewheat/wholemeal flour, traditional rolled oats, and unprocessed bran to boost fibre and nutritional benefits. 
  • Are light handed with added sugar replacing it with fresh or dried fruit or fruit purees for natural sweetness and bonus vitamins. 
  • Cut back on (or cut out) butter and incorporate your favourite good fats – poly- or mono-unsaturated oils or spreads such as canola, sunflower, olive oil etc. 
This month, we have included two recipes to get you baking the ‘better-for-you’ way – Anneka Manning’s Banana Bread and Johanna Burani’s flourless Applesauce Oat Bran Muffins with Pinoli. Pinnies on (blokes, too). Enjoy.

What’s New?

Consensus on real health benefits of low GI/GL diets. 
After reviewing all the latest research on glycemic index, glycemic load and glycemic response, an international committee of leading nutrition scientists have released a Scientific Consensus Statement that concludes that carbohydrate quality (GI) matters and that the carbohydrates present in different foods affect post-meal blood glucose (sugar) differently, with important health implications. They also confirmed that there is convincing evidence from a large body of research that low GI/GL diets reduce the risk of type 2 diabetes and coronary heart disease, help control blood glucose in people with diabetes, and may also help with weight management. They recommend including GI and GL in national dietary guidelines and food composition tables, and that packaging labels and symbols on low-GI foods should be considered. They also confirmed low GI measurements complement other ways of characterising carbohydrate foods (such as fiber and whole grain content), and should be considered in the context of an overall healthy diet.

Walter Willett, MD, DrPH, Chairman of the Department of Nutrition at the Harvard School of Public Health and one of the participating scientists said, ‘Given essentially conclusive evidence that high GI/GL diets contribute to risk of type 2 diabetes and cardiovascular disease, reduction in GI and GL should be a public health priority.’

Star-based food labelling system for Australia. 
A new voluntary front-of-pack food labelling scheme which gives a foods a star rating based on the amount of sugars, saturated fats and salt present in the food has been approved by an intergovernmental forum on food policy. ‘From a communications point of view the star system is a step in the right direction,’ comments nutritionist Bill Shrapnel. ‘However, there are problems with the suggested criteria’ he says, pointing out that:

  • Saturated fat content is only useful for assessing fat-rich foods. 
  • Using the kilojoule content of a food as a criterion is misguided. It will encourage food manufacturers to lower the fat content of foods, irrespective of the fat type. Removing unsaturated fat from foods will produce harm, not benefit. 
  • Sugar content is a poor measure of a food’s nutritional quality. In the case of packaged breakfast cereals, for some reason a priority food for the new system, sugar content is not related to nutrient density, GI, calorie content or anything else likely to affect health. If sugar is a criterion, people will be misled.’ 
Beware the low fat health halo effect. 
A recent study in Appetite that looked at the role of low-fat claims and caloric information on food intake, calorie estimates, and health attributions found that the participants both underestimated the calorie content of low-fat-labelled foods and perceived low-fat-labelled foods as healthier than regular-labelled versions of the same food. They also rated low-fat-labelled candy as significantly better tasting when they had caloric information available. The bottom line: Low-fat labelling may be a more powerful determinant of health attributions than caloric information.

What’s new on the bookshelf?  
#1 Catherine Saxelby's Ancient Grains – whole food recipes for the modern table (Arbon) provides a diverse menu of wholesome, grain-based recipes for the whole family. In her foreword to this attractive cookbook-cum-whole-grains-reference-book, Prof Manny Noakes writes: ‘We have known about the health benefits of less processed grain foods for a long time, but only recently have we had the opportunity to choose from a much wider range of grains. Among the benefits of eating whole grains that seem most appealing is the evidence that they actively assist in weight management. More particularly, whole grains seem to help with fat loss from the abdominal (tummy) region. It is not yet known why this may be the case. Is it due to the presence of fibre, the fibre type or structure, the whole grain itself, the GI of the grain, or the effect of the grain on appetite control? Some or all of these reasons are possible explanations. For weight management, having at least three serves per day of high-fibre, whole-grain, low GI foods is a good starting point.’ And that’s where this book can help. It is packed with over 100 delicious grain-based recipes (many of them low GI) including numerous gluten-free dishes for people with c0eliac disease or a gluten intolerance providing a diverse menu of recipes for all occasions for the whole family.

 Ancient Grains

The 70-plus recipes in chef Michael Moore's Blood Sugar: The Family are underpinned by his healthy eating and living philosophy that great food can be local, sustainable, flavoursome and innovative. Michael was diagnosed with diabetes at 35 and later had a stroke, so he is passionate about eating well and making sure you have lots of fresh fruit and veggies. From healthy versions of everyday meals (macaroni cheese, fishcakes, pizza, blueberry muffins) to more exotic fare (salmon tataki, rare beef salad) there's plenty here to enjoy for breakfast, lunch and dinner and snacks in between. It's certainly a book to drool over with gorgeous photographs throughout. Although we don't agree with his demonising foods like potatoes, pasta and rice (they do have a place in a healthy diet), it's good to see a book with imaginative recipes making the most of legumes, quinoa, buckwheat and barley.

Blood Sugar: The Family

Nicole's Taste of Health

Going bananas! 
Ever wondered where this came from? According to Wiki, we can trace it back to monkeys becoming somewhat intoxicated after feasting on fermented bananas that had fallen onto the forest floor and going crazy ... You could call it a natural banana daiquiri! But, it’s not just monkeys who love bananas, fermented or otherwise. They are one of the world's most popular fruits and a lunchbox favourite for kids, provided they aren’t too ripe and squishy, in which case they are perfect for cooking. Talking about going bananas, here in Australia we certainly did after Cyclone Yasi destroyed most of the crop in 2011 and bananas climbed as high as $15 a kilogram (about $3 or $4 per banana).

The banana growers of Australia are one the biggest produce grower groups and are one of only a few to advertise their product on prime time TV up against the usual fast food, confectionery and the like. I’m rather fond of their tag line “make those bodies sing” talking up the benefits to kids, and more recently “nature’s energy snack” where they contrast the ugly side of snacking on “no-nos” with the great nutrition story of “na-nas”.  And they really do compete nicely, thank you, with an economical price, ready-made packaging, portability and great eating.

Many people believe bananas are fattening – probably because they taste so good! They aren't. A medium sized banana only has around 420 kilojoules (100 calories) and really satisfies the appetite. And that creamy, mouth-filling texture is thanks to their low water content and starch-sugar combination. They are fat free. Because bananas taste sweet people often assume they are high GI but in fact they have a low GI (52). Even when they’re over-ripe and much of the starch has converted to sugar, they still fall into the low GI category.

Anneka Manning
Na-nas are a nutrition powerhouse with a bundle of nutrients along with their sustained energy. That’s why you’ll see professional cyclists (and weekend warriors) with bananas strapped to their handlebars for on-the-run refuelling. Bananas are the go-to source of potassium (my grandma tells me that), and more potassium in the diet is a good thing for helping maintain ideal blood pressure. While bananas may hide in the shadows of more trendy super-fruits, they contain antioxidants too. But they really shine for being a rich source of vitamin B6, providing a third to half the recommended daily amount. The list of good stuff in bananas also includes with B-vitamins, vitamin C and fibre.

When buying bananas, select both ripe and under-ripe fruit: bananas ripen in your fruit bowl so this ensures you have a steady supply. Because bananas emit ethylene gas as they ripen, a good trick is to place fruits you want to ripen – such as hard avocadoes – in a brown paper bag with bananas to bring them along. Keep them cool but not in the fridge which will cause their skin to go brown. Don’t be put off by dark patches on the skin as the fruit is usually still firm underneath. And if by chance they hang around long enough to become over-ripe, pop them in the freezer as they are (in their skin) and take them out as you need them for baking. Alternatively, mash them and freeze in the ice cube tray ready to pop out into a smoothie. Another idea to freeze them on a stick as natural, delicious popsicles – the kids will love ’em. Whatever the time of day, bung in a banana!


Nicole Senior is an Accredited Practising Dietitian and Nutritionist, author, speaker, consultant, and commentator with an interest in how we can learn to love good food that's good for us.

In the GI News Kitchen

Family Baking, Anneka Manning, author of The Low GI Family Cookbook (Hachette) and founder of Sydney’s BakeClub, shares her delicious ‘better-for-you’ recipes for snacks, desserts and treats the whole family will love. Anneka creates accessible recipes that really work. Through both her writing and cooking school, she teaches home cooks to bake in practical and approachable yet inspiring ways that assure success in the kitchen. Her ultimate goal is to bring real baking into your home. She wants to connect you with the magic of baking and, through this, help you nurture and connect with the people around you, especially those you love.

Anneka Manning

Banana bread. 
This recipe is a favourite in our house and I love it as much as the kids do. It includes many ingredients such as pure floral honey, bananas, buttermilk and oat bran, that are perfect for ‘better-for-you’ baking. They will help lower the GI and ensure that the kids are not only getting something delicious but also something that will give them sustained energy for their busy days. Makes 20 pieces.

Melted unsalted butter, to grease
100g (3½oz) unsalted butter, softened
½ cup single-origin floral honey
2 eggs
2 large very ripe bananas (about 400g/14oz)
1/3 cup buttermilk
1¼ cups wholemeal spelt flour
½ cup unprocessed oat bran
1½ teaspoons bicarbonate of soda
1½ teaspoons ground cinnamon

Banana bread

Preheat the oven to 180°C (350°F). Grease a 21 x 11cm/8 x 3in (base measurement) loaf pan with melted butter and line the base and the two long sides with a piece of non-stick baking paper.
Combine the butter and honey in a large mixing bowl and beat with electric beaters until well combined and creamy. Add the eggs, one at a time, beating well after each addition until well combined.
Peel and mash the bananas and stir into the mixture with the buttermilk using a spatula or large metal spoon to combine well.
Sift the flour, bicarbonate of soda and cinnamon together into a mixing bowl and return any husks to the bowl. Add the oat bran and stir to combine. Add to the banana mixture and use a large metal spoon or spatula fold in until just combined.
Spoon into the prepared loaf pan and smooth the surface with the back of a spoon. Bake in the preheated oven for 45-50 minutes or until a skewer inserted into the centre comes out clean. Stand in the pan for 5 minutes before turning onto a wire rack to cool.
Store the banana bread in an airtight container in a cool place (but not in the refrigerator) for up to 3 days.
To freeze, wrap individual slices in plastic wrap and then seal in a freezer bag or airtight container before freezing. Alternatively, pack slices in an airtight container and interleave with freezer wrap or non-stick baking paper). Thaw the slices at room temperature or toast straight from the freezer.

Per slice
500 kJ/ 120 calories; 2 g protein; 5 g fat (includes 3 g saturated fat); 16 g available carbs; 2 g fibre

Anneka's BakeTip: If you would like to replace the sugar (such as granulated white, caster or brown) with honey in a baking recipe, simply use the same amount in weight. However, also remember to reduce the amount of liquid ingredients (such as milk or water) in the recipe by 1 tablespoon for every ½ cup sugar to account for both the higher moisture level in the honey as well as its intense sweetness.

American dietitian and author of Good Carbs, Bad Carbs, Johanna Burani, shares favourite recipes with a low or moderate GI from her Italian kitchen. For more information, check out Johanna's website. The photographs are by Sergio Burani. His food, travel and wine photography website is photosbysergio.com.


Applesauce oat bran muffins with pinoli. 
Most of the time when I visit my home in northern Italy, I voraciously ask family, friends and even produce vendors for ideas and recipes they recommend for various ingredients. Sometimes, though, I become the source of such information for them. Breakfast foods would be a case in point. Italians are not the best breakfast people. Travel and the internet have led some inquisitive people to try something new. I do my part too. I’ve offered these muffins to my fast-paced relatives and friends as a perfect antidote to their beloved brioche or biscotti breakfast. I added pinoli for an Italian twist but any nut will work well.

1lb (440g) oat bran
 ½ cup brown sugar
4 teaspoons baking powder
½ cup honey
2 cups nonfat milk
2 eggs
½ cup egg substitute or 2/3 cup egg whites (about 3 extra egg whites)
¼ cup canola oil
1 cup unsweetened applesauce
½ cup pine nuts (pinoli)

 Applesauce oat bran muffins with pinoli

Preheat oven to 220°C (425°F). Spray 24 medium (1/2 cup) muffin cups with cooking spray or line with paper cups.
Combine the oat bran, brown sugar and baking powder in a large mixing bowl. In a separate, smaller bowl, combine the remaining ingredients. Add wet ingredients to the large bowl and mix well.
Fill the muffin cups three-quarters full. Bake 17–20 minutes or until the muffin tops are browned. Cool before serving. These muffins freeze well.

Per serve 
720kJ/170 calories; 5g protein; 7g fat (includes 0.5g saturated fat); 24g available carbs; 3g fibre

Here's how you can cut back on the food bills and enjoy fresh-tasting, easily prepared, seasonal, satisfying and delicious low or moderate GI meals that don’t compromise on quality and flavour one little bit with our Money Saving Meals including this Brown rice, chicken and vegetable soup with chipotle chili and lime reproduced with permission from Catherine Saxelby’s new book, Ancient Grains: whole-food recipes for the modern table (Arbon AUD $34.99)

Brown rice, chicken and vegetable soup with chipotle chili and lime.
Don’t leave out the fresh lime – it is an important flavor booster for this gluten-free soup. For those who like it hot and spicy, serve extra chipotle chili in a side bowl. Serves 4.

Chicken stock
4 chicken drumsticks (skin removed)
4 chicken wings
8 cups water
1 large white onion, quartered
2 garlic cloves, peeled and halved
1 teaspoon flaked salt
8 black peppercorns

1 tablespoon sunflower oil
1 medium white onion, finely chopped
1 garlic clove, chopped
1 large carrot, diced
½ cup medium grain brown rice
7 oz/200 g zucchini (courgette) diced
1 fresh corncob, kernels removed flaked
salt to taste

To serve
4 chipotle chilies from a can
1 small, firm, ripe avocado, chopped
fresh cilantro (coriander) sprigs
lime quarters

Brown rice, chicken and vegetable soup with chipotle chili and lime.

To make the chicken stock, place the chicken pieces, water, onion, garlic, salt, and peppercorns into a large, heavy-based saucepan. Cover and bring to the boil over medium–high heat. Reduce the heat to low, and simmer with the lid slightly ajar for 30 minutes.Remove the lid, and cook the chicken stock for a further 30 minutes or until the liquid has reduced by half. Remove the chicken pieces from the stock, and set the liquid aside to cool slightly. Discard the cooked wings, and then remove the skin from the drumsticks. Pull the flesh into fine shreds; place the shredded chicken on a plate, cover, and store it in the refrigerator until it is required. Strain the stock into a container. If required, top up the stock with water to about 4 cups. Wipe the saucepan out with a kitchen paper towel.
To make the soup, heat the sunflower oil in the saucepan over medium heat, and add the onion, garlic, carrot, and rice. Cook the mixture for 5 minutes, stirring the whole time. Add the chicken stock, and then bring the soup to the boil. Reduce the heat to low, and simmer with the lid slightly ajar for 50 minutes or until the rice is tender. Increase the heat to medium, and add the zucchini and corn kernels. Bring the soup to the boil, and then reduce the heat to low and simmer, covered, for 10 minutes. Taste and season with salt if you wish.
To serve, place the chipotle chilies onto a plate, and cut each chili in half. Divide the soup evenly between four serving bowls, and top each with some shredded chicken, chipotle chili, avocado, and cilantro (coriander). It is best to mix the chipotle chili through the soup. Serve the soup immediately, along with lime quarters to squeeze over the liquid.

Per serve 
2375 kJ/ 570 calories; 43 g protein; 27 g fat (includes 6 g saturated fat); 32 g available carbs; 7 g fibre

We Are What We Ate

The clockwork body – why when we eat matters. 
‘Body clocks are ancient mechanisms that regulate fundamental biological systems important to health, such as insulin secretion, the time we go to bed, the time we get up and the time we get hungry,’ says Dr Joe Bass, associate professor of medicine at Feinberg School of Medicine and of neurobiology and physiology at the Weinberg College of Arts and Sciences.

Body clock

The body’s primary circadian clock resides deep in the brain, in the suprachiasmatic nuclei, but local biological clocks also are found in tissues throughout the body, including the pancreas, lungs, liver, heart and skeletal muscles. The clocks operate on a 24-hour, circadian (Latin for about a day) cycle that governs functions such as sleeping and waking, rest and activity, fluid balance, body temperature, cardiac output, oxygen consumption, metabolism and endocrine gland secretion.

How the circadian clock may affect the development of diabetes: A study by Bass and colleagues published in Nature in 2010 showed that insulin-secreting islet cells in the pancreas, called beta-cells, have their own dedicated clock. The clock governs the rhythmic behavior of proteins and genes involved in insulin secretion, with oscillations over a 24-hour cycle. ‘This is the first evidence of how the circadian clock may affect the development of diabetes’ said Bass. ‘The biological programs in animals for harvesting energy -- much like the photosynthesis of plants -- are under control of the clock. Our findings will help us figure out the causes of glucose abnormalities, but we still have a lot to learn.’

How the circadian clock may affect weight gain: Dr Steven Shea, director for the Center for Research on Occupational and Environmental Toxicology at Oregon Health and Science University and colleagues at Harvard report in a study published in Obesity that the body’s internal clock, the circadian system, increases hunger and cravings for sweet, starchy and salty foods in the evenings. While the urge to consume more in the evening may have helped our ancestors store energy to survive longer in times of food scarcity, in the current environment of high-calorie food, those late night snacks may result in significant weight gain.

‘Of course, there are many factors that affect weight gain, principally diet and exercise, but the time of eating also has an effect. We found with this study that the internal circadian system also likely plays a role in today’s obesity epidemic because it intensifies hunger at night,” said a senior author on the study. “People who eat a lot in the evening, especially high-calorie foods and beverages, are more likely to be overweight or obese.’

Indeed, eating a lot in the evening can be counterproductive since the human body handles nutrients differently depending on the time of day. For example, glucose tolerance may be impaired in the evening. Additionally, consuming more calories in the evening predisposes people to more energy storage; we simply don’t expend as much energy after an evening meal in comparison to morning meals.

Furthermore, artificial light enables people to stay up later than they probably should and often people don’t get enough sleep. ‘If you stay up later, during a time when you’re hungrier for high-calorie foods, you’re more likely to eat during that time,’ Shea said. ‘You then store energy and get less sleep, both of which contribute to weight gain. If weight loss is a goal, it’s probably better to eat your larger, higher-calorie meals earlier in the day,’ said Shea. “Knowing how your body operates will help you make better choices. Going to bed earlier, getting enough sleep and choosing lower-calorie foods rather than higher-calorie foods in the evening can all help with weight loss.’

GI Symbol News with Dr Alan Barclay

Alan Barclay
Dr Alan Barclay
Low GI, gluten-free foods. 
Coeliac disease is becoming increasingly common, affecting around 1 in 100 people in Australia and the UK, and 1 in 133 Americans.

People with coeliac disease’ own immune system reacts abnormally to the protein gluten found in wheat, rye, and barley (and often a contaminant in oats, depending on where you live), causing damage to their small intestine. The tiny, finger-like projections known as villi which line the small intestine become inflamed and flattened – a condition known as villous atrophy. As a consequence, the surface area of the intestine available for the absorption of nutrients is reduced which can lead to various gastrointestinal and malabsorptive symptoms like diarrhoea and/or constipation, large, bulky foul stools, unwanted weight loss or poor growth in children, flatulence, abdominal bloating, distension or pain, and anaemia. Long-term complications can be very serious and include infertility, miscarriage, depression and dental enamel defects. There is also an increased risk of developing certain forms of cancer such as lymphoma of the small bowel.

If you have a family history of coeliac disease, some or even all of these symptoms, it’s important that you don’t simply self-diagnose coeliac disease and commence a gluten free diet. A diagnosis of coeliac disease can only be made by demonstrating the typical villous atrophy of coeliac disease in a small bowel biopsy. This involves a gastroscopy procedure in which several tiny samples of the small bowel are taken and examined under a microscope. Importantly, you must still be eating gluten regularly before the procedure is performed or you may get a false negative result.

For reasons that we do not yet completely understand, people with type 1 diabetes are at much greater risk (up to 10 times) of developing coeliac disease than people who do not have type 1 diabetes. Both coeliac disease and type 1 diabetes are autoimmune diseases that are ‘triggered’ in genetically susceptible people by as yet unknown environmental factors. Coeliac disease can make management of blood glucose levels even harder than usual in people with type 1 diabetes, with increased risk of both hyper and hypoglycaemia. People with type 2 diabetes or pre-diabetes are thought to have the same level of risk as the rest of the population.

A gluten free diet is currently the only known treatment for coeliac disease and unfortunately it is for life because people with coeliac disease remain sensitive to gluten throughout their life – the condition can never be cured as such. By removing the cause of the disease, a gluten free diet allows the small bowel lining to heal and symptoms to resolve. As long as the gluten free diet is adhered to as strictly as possible, problems arising from coeliac disease should not return.

In the not-too-distant past, having to consume a gluten free diet used to be a culinary disaster. Thankfully, food industry has stepped up to the proverbial plate and there is now just about a gluten free alternative for most of your favourite foods. Many gluten-free core foods like milk, yoghurt, some starchy vegetables, legumes and most fruits also have a low GI. However, many gluten free grain alternatives aren’t low GI, so finding gluten free breads, pasta, breakfast cereals, etc. can still be a challenge. For more information, check out the Low GI Diet for Gluten-free Cooking (ANZ edition; Hachette Australia) or Low GI Gluten-free Eating Made Easy (US/Canada edition; Da Capo).

The GI Foundation has been working with Coles to develop their home-brand range of low GI gluten free foods with real flavour. First on the shelves are five pasta and quinoa products that all carry the GI Symbol.

Coles Simply Gluten Free: 

  • Spaghetti: GI46
  • Spirals: GI46
  • Penne: GI46
  • 2 Quinoa Cups: GI53 
  • 2 Mexican Style Quinoa and Brown Rice Cups: GI49.
Coles Quinoa Cups

The GI Symbol, making healthy low GI choices easy choices

New GI Symbol

For more information about the GI Symbol Program
Dr Alan W Barclay, PhD
Chief Scientific Officer
Glycemic Index Foundation (Ltd)
Phone: +61 (0)2 9785 1037
Mob: +61 (0)416 111 046
Fax: +61 (0)2 9785 1037
Email: alan.barclay@gisymbol.com
Website: www.gisymbol.com

GI Update with Prof Jennie Brand-Miller

Prof Jennie Brand-Miller answers your questions. 


Can you explain the difference between glycemic index, glycemic load and glycemic response? 
Glycemic Index (GI) is a measure of the quality of carbohydrate. It compares carbohydrates, gram for gram, in one food versus another. 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) is a measure of both the quality and quantity of carbohydrate. How high your blood glucose actually rises and how long it remains high when you eat a meal containing carbohydrate depends on both its GI and the amount 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. GL per 1000 kJ has been shown to be the single best predictor of actual glycemic responses to single foods and mixed meals.

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, high or low. The glycemic response varies from person to person, depending on their 'glucose tolerance'. A person with diabetes or impaired glucose tolerance will have a higher glycemic response to any food than a lean, young, healthy individual. Nonetheless, in a single individual, we can reliably predict that a low GI/GL meal will produce a lower glycemic response than a high GI/GL meal.

GI testing by an accredited laboratory
North America

Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Email info@gilabs.com
Web www.gilabs.com

Fiona Atkinson
Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
Sydney University
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022
Email sugirs@mmb.usyd.edu.au
Web www.glycemicindex.com

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