1 May 2013

GI News—May 2013


  • Why some of us can digest milk - and others can't;  
  • Milk and yoghurt: nutritious, inexpensive and low GI foods for the whole family; 
  • As our waistlines have expanded, so have those of our pets; 
  • Cuba: how an economic downturn led to a health upturn;  
  • Low carb diets don't help women with gestational diabetes; 
  • The scoop on potassium; 
  • Four recipes to try.  
GI News 
Editor: Philippa Sandall
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Food for Thought

Even our pets are fat … 
I took a sneak peak at our much loved and seriously plump puss some years ago when I read ‘even our pets are fat’ in the first chapter of Prof Jennie Brand-Miller’s original manuscript for The Low GI Diet. Today our much loved Silkie is a rather streamlined 6kg. We fed him less and played with him more – he particularly likes pelting a ping pong ball back at you. It wasn’t easy. It wasn’t speedy. And we had to harden our hearts to much pathetic yowling in front of cupboard and fridge doors. But now he really does seem to ‘eat to appetite’. Mostly ...

Silky the cat

Worldwide, as our waistlines have expanded, so have those of our pet animals (and animals in zoos). In the US, the sixth annual National Pet Obesity Awareness Day Survey conducted by the Association for Pet Obesity Prevention (APOP) in 2012 found 52% of dogs and 58% of cats to be overweight or obese. That equals approximately 80 million US dogs and cats at increased risk for weight-related disorders such as diabetes, osteoarthritis, hypertension and many cancers. It’s generally considered that we pet owners are the problem and in the wild animals are lean. But it’s a bit more complicated than just calories in/calories out as Dr Barbara Natterson-Horowitz reports in her new book, Zoobiquity.

Evolving Health blogger David Despain has had a long-held fascination with the topic of how health in the animal world relates to the human world. He recently chatted with Dr Barbara Natterson-Horowitz and we reproduce an excerpt of that interview here with his kind permission.

David Despain: Being a nutritionist, one of my favorite chapters in your book was ‘Fat Planet’ where you tell the story of two obese Alaskan grizzlies Jim and Axhi who were treated at Chicago's Brookfield Zoo by nutritionist Jennifer Watts. Watts changed their diet and lifestyle in ways that was informed by knowledge of their natural ecology. It wasn’t a ‘perfect wild diet’ – as that’s fantasy – but there were changes like considering the environment’s cyclical periods of abundance and scarcity as well as season’s effect on their intestinal microbiomes. Previously, I’ve written about nutritionists doing similar things both with lemurs that suffer from obesity and diabetes. What would you say are the key takeaways in dietary advice that humans can learn from your examples?

Dr Barbara Natterson-Horowitz: There were so many surprises that we encountered in researching the book. One early misconception that we bumped up against was this idea that only human beings overeat. There seems to be this fantasy that animals in their natural setting have internal regulatory systems that would result in eating only to satiety and that would be it. This idea was so wrong. We now understand that, actually from an evolutionary perspective, animals that are likely to encounter periods of scarcity do [overeat] when they encounter periods of abundance ... [then] they absolutely over-consume and sometimes spectacularly over-consume. That was already the beginning of a set of really surprising findings. If there’s abundance and there's no predatory threat, they’ll just consume and consume.

The other real biggie was that … it’s pretty much been assumed until very recently that it was all about calories in, calories out. I think most physicians have had patients that say they are not losing weight, and they swear to you that they’re eating 900 calories a day – do you really think that that’s true? I think most physicians would be skeptical and think that their patients are probably not telling the truth or not aware of how much they’re eating.

So, one of the exciting and surprising aspects of researching this chapter was to learn about all of these other factors that go beyond calories in and calories out. These could very well be influencing metabolism in both individual human patients and other species as well – things like the seasonal microbiome, and circadian variation, even climate change, endocrine-modifying chemicals, and perhaps antibiotics in the environment. These are really interesting ideas to think about even in [the context of] the obesity epidemic as not being isolated to human beings, but perhaps being more species-spanning.’

 – In Zoobiquity: The Astonishing Connection Between Human and Animal Health, you'll learn all sorts of interesting facts: that dinosaurs also suffered from cancer, that fish faint, that horses suffer from sexual dysfunction, that all sorts of wild animals can at times develop eating disorders or overeat and become obese, that koalas suffer from chlamydia, that birds self-injure, and that wallabies get stoned. The term ‘zoobiquity’ was coined by UCLA cardiology Professor Barbara Natterson-Horowitz, MD, and science journalist Kathryn Bowers to describe their call for a coming together of three scientific fields: human medicine, veterinary medicine, and evolutionary biology. It's available from good bookshops and online.

What’s New?

Canada’s new diabetes guidelines recommend low GI carbs. 
The online release the Canadian Diabetes Association includes the full text of all 38 chapters and an appendix. Each chapter comes with a slide set and a brief video highlighting the key recommendations. There are also accompanying tools for health care providers and resources for patients. Here are the Key Nutrition Therapy Messages:

  • People with diabetes should receive nutrition counselling by a registered dietitian. 
  • Nutrition therapy can reduce glycated hemoglobin (HbA1C) by 1.0% to 2.0% and, when used with other components of diabetes care, can further improve clinical and metabolic outcomes. 
  • Reduced caloric intake to achieve and maintain a healthier body weight should be a treatment goal for people with diabetes who are overweight or obese. 
  • The macronutrient distribution is flexible within recommended ranges and will depend on individual treatment goals and preferences. 
  • Replacing high glycemic index carbohydrates with low glycemic index carbohydrates in mixed meals has a clinically significant benefit for glycemic control in people with type 1 and type 2 diabetes. 
  • Intensive lifestyle interventions in people with type 2 diabetes can produce improvements in weight management, fitness, glycemic control and cardiovascular risk factors. 
  • A variety of dietary patterns and specific foods have been shown to be of benefit in people with type 2 diabetes. 
  • Consistency in carbohydrate intake and in spacing and regularity in meal consumption may help control blood glucose and weight. 
The guidelines are accessible here.

Low carb diets don’t help women with gestational diabetes
Dr Kate Marsh of Northside Nutrition and Dietetics and co-author (with Prof Jennie Brand-Miller) of The Low GI Eating Plan for an Optimal Pregnancy comments on a recent study in Diabetes Care that has shown that a low carb diet in women with gestational diabetes didn’t reduce the number of women needing insulin or affect pregnancy outcomes.

Kate Marsh
Dr Kate Marsh

‘Carbohydrate foods (e.g. breads, cereals, grains, rice, pasta, legumes, starchy vegetables, fruit, milk and yoghurt) break down to glucose and directly affect blood glucose levels. For women diagnosed with gestational diabetes during their pregnancy, eating the right amount and types of carbs is therefore essential for keeping blood glucose levels in the target range. While some women may think that just cutting down on carbs is the answer, this new study has shown that a low carb diet in women with GDM didn’t reduce the number of women needing insulin. Many carbohydrate foods (e.g. wholegrains, fruit and dairy) are important in helping to meet nutritional needs during pregnancy, and very low carbohydrate intakes during pregnancy can be detrimental to a growing baby. Previous research has shown that a low GI diet (where carbohydrate intake is similar but the types of carbs are changed to lower GI options) can reduce insulin requirements in women with GDM, which in conjunction with these latest findings suggests that choosing the right carbs rather than necessarily cutting down carbs (unless intake is particularly high), is the key to managing blood glucose levels in pregnancy.’

Low carb diets? Not for the long haul.
A growing body of evidence suggests that low-carb diets and their combination with high-protein diets are effective in weight loss – they are certainly popular. In addition, they may have favourable short-term effects on risk factors of cardiovascular disease. However, it now seems there could be serious health implications if people consume a low-carb diet for a long period of time. When Hiroshi Noto and his co-authors, from the University of Japan reviewed 17 long-term studies into low carb diets published in PLOS ONE, they found that low-carb diets were in fact associated with a significantly higher risk of all-cause mortality. ‘Low-carbohydrate diets tend to result in reduced intake of fibre and fruits and increased intake of protein from animal sources, cholesterol and saturated fat. In their conclusion they write: ‘Our meta-analysis supported long-term harm and no cardiovascular protection with low-carbohydrate diets. … Our findings underscore the imminent need for large-scale trials on the complex interactions between low-carbohydrate diets and long-term outcomes.’

Cuba: how an economic downturn lead to a health upturn.
A recent study in the BMJ suggests that initiatives that encourage people to eat less and exercise more could achieve significant positive health outcomes. The findings are based on the Cuban experience in 1980–2010. During the early 1990s, Cuba suffered an economic downturn due to a tight US embargo on imports and the collapse of the Soviet Union, which had been supporting the country. This led to a drop in the number of calories consumed in the average Cuban diet. Due to the embargo, petrol became virtually unobtainable, and more than 1 million bicycles were distributed by the government, leading to an increase in physical activity. These factors contributed to an average weight reduction per citizen of 5.5kg over the course of the five-year economic crisis. During this time there was a significant drop in prevalence of, and deaths due to, cardiovascular diseases, type 2 diabetes and cancers. But once the crisis was over and people started to eat more and exercise less, these trends began to reverse. The question is how, in an affluent and free Western democracy, do you encourage people to eat less and exercise more?

Bicycling in Cuba

Commenting on this study, Prof Walter Willet writes: ‘Physicians can help promote healthy social norms by visibly engaging in healthy behaviors. On a recent trip to Cuba, I had hoped to see Havana by borrowing one of the million bicycles that had been distributed. However, there were virtually no bikes, bike riders, or bicycle lanes to be seen; and several people told me that bicycles reminded them of earlier economic hardships. In many countries, walking and bicycle riding are regarded as lower class behaviors. Boston celebrates the example set by Paul Dudley White, probably the most famous cardiologist in America and personal physician to President Eisenhower, who rode his bicycle daily to Massachusetts General Hospital into his 80s. The city named a bike path in his honor, and it is currently expanding its bicycle parking facilities. Dr White may have saved more lives by his bike riding than by putting stethoscope to flesh.’

The Low GI Eating Plan for an Optimal Pregnancy. 
The Low GI Eating Plan for an Optimal Pregnancy (The Experiment Publishing) helps a mom-to-be understand the connection between the food she eats, her blood glucose levels, and her baby’s future health. The focus is on low GI carbohydrates – vital at this time, because reducing dietary GI is one of the safest and most effective ways to ensure that baby grows at the optimal rate, without mom gaining excessive body fat and without compromising nutrition. One of the authors, Prof Jennie Brand-Miller, explains why: ‘Pregnancy is a stage in life when carbs play a starring role. This is because a Mom’s average blood glucose level throughout the day is directly correlated with her baby’s growth rate in the womb. Quite simply, glucose is the primary fuel that drives all aspects of her baby’s development. If her glucose levels are too high, then her baby will grow too fast and be born with excessive amounts of body fat. Conversely, if her glucose levels are too low, baby’s growth might be too slow.’

Kate Marsh
– Published in Australia in 2012 as The Bump to Baby Diet.

Online updates.
#1 Here's a blog that’s just the recipe for women with GDM After having gestational diabetes (GDM), Lisa Taylor created the Gestational Diabetes Recipes website with dietitian Natasha Jo Leader because she loves food. With this recipe blog, she hopes women are able to turn their diagnosis of GDM into a more positive experience that allows them to continue to enjoy delicious food and their pregnancy but be mindful of the importance of healthy eating and lifestyle for the long term for both themselves and their children. You can try Lisa’s recipes here.
#2 Having worked as an author, food editor, writer, consultant, teacher and publisher for some 23 years, Low GI Family Cookbook co-author, Anneka Manning, has now started the BakeClub. This is a cooking school where you can learn to create baked goodies online or by attending classes and workshops. Classes start in May in Sydney, Australia. First up (11 May) is a three-hour workshop on creating snacks for healthy kid’s lunch boxes (and for after school, too). In the workshop, store-bought muffins, muesli bars, biscuits and cakes will be compared with healthier, more natural home-baked versions then you learn how easy it is to fill lunch boxes with these ‘better for you’ sweet and savory alternatives, that you will feel good about and your kids (and their friends) will enjoy. You can find out more about this workshop here.

Anneka Manning
Anneka Manning

Get the Scoop

The scoop on potassium.
Last year in GI News, dietitian Emma Stirling gave us the scoop on a study published in the American Journal of Clinical Nutrition that investigated links between potassium levels and incidence of diabetes. That study found that as potassium levels went up, the incidence of diabetes went down. The African Americans in the study were found to have lower average potassium levels than the Caucasians and were twice as likely to develop type 2 diabetes.

A new study in the British Medical Journal reports that that as potassium goes up, risk of stroke goes down. The researchers examined studies involving over 128,000 healthy participants and found that those with the highest potassium intake had a 24% lower risk of stroke. They also found that high potassium reduced blood pressure in people with hypertension and had no adverse effects on people with normal blood pressure and kidney function.

‘Potassium is a great mineral to have on board,’ says Emma. ‘It acts as a complementary mineral to sodium and can help achieve a healthy blood pressure. The best bet approach is to focus on a nutrient-rich eating plan with plenty of potassium-rich foods like nuts, dried and fresh fruit, wholegrains including bran and wheatgerm, raw vegetables, lean meat and fish. By far the most well known source of potassium is the banana. The average banana (GI 52) provides around 20g carbohydrate and around 350mg of potassium (about 10% of your daily needs). Time to wake up to a smoothie?’

In the GI News Kitchen

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.


Sergio’s eggs ‘al tegamino’.
My husband, Sergio, grew up in post-World War II war-torn northern Italy. Food was not plentiful but fresh eggs were always available, though not in excess. His family, like most other families in the neighborhood, owned one or two hens that they could always rely on for an evening’s meal. Sergio ate eggs ‘al tegamino’ (in a little pan) at least once a week back then. He loves to make this recipe nowadays – for the good taste and for the good memories. Makes 1 serving.

1 teaspoon butter
2 eggs pinch salt (a pinch is about 1/8 tsp)
pinch dried thyme
pinch dried basil

Sergio’s eggs ‘al tegamino'

Melt the butter in a small frying pan (Sergio uses a cast iron one) over a low flame.
Crack the eggs into a little pan one at a time, piercing the yolks with a fork. Sprinkle over the salt and herbs and cook the eggs slowly, uncovered, for approximately 8 minutes or to your preferred consistency. Serve immediately.

Per serve
740kJ/177 calories; 13g protein; 14g fat (includes 5g saturated fat); 1g available carbs; 0g 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 Body Playground Emma Sandall’s Quinoa salad with lentils, fennel and orange.

Quinoa salad with lentils, fennel and orange.
Serves 4

½ cup Puy lentils
1 bay leaf
1 cup quinoa
3 tbsp hazelnuts, roasted and roughly chopped
Bunch flat-leaf (Italian) parsley, well washed, finely chopped
1 tbsp ground cumin
3–4 fresh dates, pitted and chopped
1 lemon, juiced
½ green capsicum, seeded and diced
½ red capsicum, seeded and diced
½ orange, thinly sliced into rounds and cut into quarters
½ fennel bulb, finely sliced
Small bunch radishes, finely sliced (about 6 radishes)
Olive oil
Small head witlof, leaves separated and roughly torn

Quinoa salad with lentils, fennel and orange

Cook the lentils in boiling water with the bay leaf until done (about 20–25 minutes). Drain in a sieve and set aside to cool. Discard the bay leaf. Meanwhile …
Place the quinoa in a saucepan of cold water, bring to the boil and simmer for 8–9 minutes. Drain in a fine sieve, rinse under cold water and set aside to dry.
Macerate the dates in small bowl with cumin and lemon juice
Combine the lentils and quinoa in a mixing bowl with the hazelnuts, parsley, capsicum, and the date mixture. Drizzle over 1–2 tablespoons of olive oil and gently combine with a fork to achieve the right taste and texture. To serve, arrange the witlof in a serving bowl and top with scoops of the grain mixture and the slices of orange, fennel and radishes.

Per serve 
1380kJ/330 calories; 15g protein; 10g fat (includes 1g saturated fat); 44g available carbs; 11g fibre

Mini bread & banana puddings. 
This is one of blogger Lisa Taylor's recipes on her gestational diabetes recipes blog. You can also find it in The Low GI Eating Plan for an Optimal Pregnancy. Lisa says you can serve these little puddings with a small dollop of reduced-fat ice-cream or reduced-fat custard if you like. However, they are simply delicious as is! Serves 4.

1 tbsp light cooking oil for greasing ramekins
2 cups skim milk
2 large eggs
2 small bananas, mashed
1 tsp vanilla extract
1 tsp ground cinnamon
6 slices low GI seed or multigrain bread, crusts removed, halved diagonally
½ cup blueberries (frozen or fresh)
Reduced-fat ice cream for serving if desired

Mini bread & banana puddings

Preheat oven to 170°C (350°F). Lightly grease 4 individual ramekins (or a baking dish) with oil. Set aside.
Whisk together milk, eggs, mashed banana, vanilla extract and cinnamon in a large bowl until combined. Soak each piece of bread in the milk mixture for a few seconds.
Place 4 of the bread triangles in baking dish or 1 in each individual ramekin, scatter with one-third of the blueberries then spread with a little of the milk mixture. Repeat layering process until all the bread triangles have been used. Pour over any remaining milk mixture and blueberries then sprinkle lightly with a little more cinnamon.
Bake for 35–40 minutes or until puffed and golden. Serve with a small dollop of ice cream if desired.

Per serve (without ice cream)
1090kJ/260calories; 13g protein; 6g fat (includes 1g saturated fat); 37g available carbs; 6g fibre

We Are What We Ate

Milk – poster child for rapid evolution in humans.  
Marlene Zuk, a professor of ecology, evolution, and behavior at the University of Minnesota, describes milk – or more accurately the ability to digest it – as ‘the poster child for rapid evolution in humans.’ In Paleofantasy she explains how this ability came about, what it means at the genetic level, and what its consequences have been.

Milking camels

‘The first thing you have to do to study 4,000-year-old DNA is take off your clothes,’ writes Marlene Zuk in her introduction to Paleofantasy. ‘I am standing with Oddný Ósk Sverrisdóttir in the air lock room next to the ancient-DNA laboratory at Uppsala University in Sweden, preparing to see how she and her colleagues examine the bones of human beings and the animals they domesticated thousands of years ago. These scientists are looking for signs of changes in the genes that allow us to consume dairy products past the age of weaning, when all other mammals lose the ability to digest lactose, the sugar present in milk. After that time, dairy products can cause stomach upsets. But in some groups of humans, particularly those from northern Europe and parts of Africa, lactase - the enzyme that breaks down lactose - lingers throughout life, allowing them to take advantage of a previously unusable food source. Oddný and her PhD supervisor, Anders Götherström, study how and when this development occurred, and how it is related to the domestication of cows for their meat and milk. They examine minute changes in genes obtained from radiocarbon-dated bones from archaeological sites around Europe ...

To obtain the DNA, the bones are drilled and the powder from the interior is processed so that the genetic sequences inside are amplified - that is, replicated to yield a larger amount of material for easier analysis. Some bones are more likely to be fruitful than others; we heft the samples, since Oddný says that the most promising ones are heavy for their size, and glossy. Most of the samples are about 4,000 years old, but one of them is around 16,000 years old. It has already been rendered into powder, and I look at it closely, but it doesn’t seem any different from the others. One of the pieces is a flat section of skull, while others are sections of leg or arm bones, or a bit of pelvis. Oddný and I wonder briefly who all these people were, and what their lives were like. The details of their experiences, of course, are lost forever. But the signature of what they were able to eat and drink, and how their diet differed from that of their - our - ancestors, is forever recorded in their DNA.

Other than simple curiosity about our ancestors, why do we care whether an adult from 4,000 years ago could drink milk without getting a stomach ache? The answer is that these samples are revolutionizing our ideas about the speed at which our evolution has occurred, and this knowledge, in turn, has made us question the idea that we are stuck with ancient genes, and ancient bodies, in a modern environment. We can use this ancient DNA to show that we are not shackled by it.’


Adapted from Paleofantasy: What Evolution Really Tells Us About Sex, Diet, and How We Live by Marlene Zuk. Copyright © 2013 by Marlene Zuk. With the permission of the publisher, W.W. Norton & Company, Inc. Distributed in Australia by Wiley. In Paleofantasy, Marlene Zuk draws on fascinating evidence that examines everything from our ability to drink milk as adults to the texture of our ear wax to show that we’ve actually never stopped evolving. Our nostalgic visions of an ideal evolutionary past in which we ate, lived, and reproduced as we were “meant to” fail to recognize that we were never perfectly suited to our environment. Evolution is about change, and every organism is full of trade-offs.

GI Symbol News with Dr Alan Barclay

Alan Barclay
Dr Alan Barclay

Milk and yoghurt: nutritious and inexpensive low GI foods for the whole family. 
Dairy foods like milk and yoghurt are great sources of essential nutrients like calcium, magnesium, zinc, vitamin A, riboflavin (B2), B12, protein and low GI carbs. Generally we recommend reduced or low fat varieties for most people over the age of two as they provide considerably less calories. All plain milks (GI 20–34) and yoghurts (GI 11–19) have very low GI values, due to the fact that the carbohydrate is lactose – a low GI sugar (GI 46). On average 1 cup of milk provides 12–13 grams of carbohydrate, and 1 cup of plain yoghurt 12–15 grams. The unique amino acids found in milk proteins that help promote insulin secretion also contribute to their low GI. Although all high quality protein foods (that includes meat, fish and eggs) stimulate insulin secretion, it’s possible that the proteins in milk may promote more because they are uniquely designed to help young mammals grow and develop. Despite this, these dairy foods are not associated with an increased risk of developing type 2 diabetes – the opposite in fact is the case.

Because not everyone likes to drink or eat plain milk or yoghurt, they are often sweetened with honey, other added sugars (e.g. sucrose) or alternative sweeteners (e.g. aspartame, sucralose), fruit, chocolate (e.g. cocoa) or other flavours (e.g. vanilla) to increase their palate appeal. Although added fruit and nutritive sweeteners may increase the GI of milk (GI 29–45) and yoghurt (29–44) and the amount of carbohydrate in a serve, they remain highly nutritious, low GI foods overall. It’s also easy to ‘sweeten’ your favourite reduced or low fat plain milks and yoghurts yourself with fresh or canned fruit, low GI sweeteners like Logicane™ or wildflower honeys (e.g. yellow box), or a low GI flavouring such as Milo™. Live probiotic bacteria can be added to any type of yoghurt.

What yoghurt is that? 

  • Set (or ‘pot set’) yoghurt tends to be fairly thick and not have any whey separation. It is fermented and set at controlled temperatures in individual tubs.
  • Stirred yoghurt is the most popular variety on our supermarket shelves. It is bulk-fermented then pumped through a cooler, the fruit or flavouring is stirred in and it is packaged in individual containers.
  • Drinking yoghurt is produced similarly to stirred yoghurt.
  • Soft serve/frozen yoghurt starts out as stirred yoghurt. To maintain its smooth texture on freezing, a blend of sweeteners, stabilisers, emulsifiers (and flavours) is added. 
Frozen berry yoghurt 
Anneka Manning's frozen yoghurt from The Low GI Family Cookbook  is perfect for desserts or snacks and serves 6.

250g (9oz) fresh or frozen mixed berries
3 x 200 g (7oz) tubs low fat vanilla yoghurt
2 egg whites
2 tbsp floral honey

Anneka Manning's frozen yoghurt

Place the berries and yoghurt in a food processor and blend until smooth. Transfer to a medium-sized bowl and set aside. Whisk the egg whites in a clean, dry bowl until stiff peaks form. Add the honey a tablespoon at a time, whisking well after each addition until thick and glossy. Fold into the berry yoghurt mixture until just combined. Pour the mixture into an airtight container and place in the freezer for 4 hours or until frozen. Use a metal spoon to break the frozen yoghurt into chunks. Blend again in a food processor until smooth. Return to the airtight container and refreeze for 3 hours or until frozen. Serve in scoops.

Per serve 
Energy: 540kJ/ 129cals; Protein 7g; Fat 0.3g; Carbs 22g; Fibre 1g

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. 


What’s wrong with a low carb diet? 
Recent studies show that low carb diets can produce faster rates of weight loss than conventional low fat diets. The probable mechanism is lower day-long insulin levels – allowing greater use of fat as the source of fuel – the same mechanism underlying the success of low GI diets.

Low carb diets are relatively safe and effective for weight loss in the short term, but there are potential risks in the long term (longer than six months). One major concern is the potential for high saturated fat intake and the repercussions from that intake. Even a single meal high in saturated fat can have an adverse effect on blood vessels by inhibiting vasodilation, the normal increase in the diameter of blood vessels that occurs after a meal. A short-term and long-term effect of a low carb diet includes an increase in LDL cholesterol. Compounding this, there may be a low intake of miconutrients that are protective against disease. For this reason, a vitamin and mineral supplement is an essential accompaniment to a low carb diet. Low carb diets are often high in protein (although not all high-protein diets are low in carbohydrate). In people with diabetes, higher long-term protein loads (over six months) may accelerate decline in kidney function and increase calcium loss in urine, potentially increasing the risk of osteoporosis and kidney stones.

We believe that low carb diets are unnecessarily restrictive (bread, potato, rice, grains and most fruits are restricted) and may spell trouble in the long term if saturated fat takes the place of carbohydrate. Low GI diets strike a happy medium between low fat and low carb diets – you can have your carbs, but must choose them carefully. 

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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