The Diogenes children’s study
In December GI News we reported the findings of the Diogenes Study, which was set up to investigate whether people who have undergone recent major weight loss could maintain that lower weight. The researchers reported that: ‘A modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss.’
Professor Arne Astrup
To recap, the research team led by Professor Arne Astrup at the University of Copenhagen randomly assigned 773 adults who had previous lost an average of 11kg to one of five diets for a 26-week intervention period. These were not calorie controlled diets – those taking part could eat as much food as they liked from their assigned diet group. Participants were on average 41 years old and were all parents. Their children, although not part of the trial, were assigned to the same diets. All five diets were designed to have a moderate fat content (25–30% of total energy). The diets were:
- Group 1: Low protein (13% energy consumed), low GI
- Group 2: Low protein, high GI
- Group 3: High protein (25% energy consumed), low GI
- Group 4: High protein, high GI
- Group 5: Control diet which followed current dietary guidelines without special instructions regarding GI or protein levels
The results of the children’s study have been published in Pediatrics. In the families, there were 827 children who only participated in the second part of the program, the diet intervention stage. Thus, they were never required to go on a diet or count calories – they simply followed the same ab libitum diet as their parents. Approximately 45% of the children in these families were overweight. The results of the children’s study were remarkable: in the group of children who maintained a high-protein (21.4% of calories), lower-GI (56.9) diet the prevalence of overweight dropped spontaneously from approximately 46% to 39% – a decrease of approximately 15%.
Paddock2Plate is a new feature where we share produce stories from food and nutrition blogs that caught our eye and we think may catch yours.
#1 Australia’s home-grown chickpeas Making the most of chickpeas in your meals is a great way to reduce the overall GI of your diet. But chickpeas are not only good for us, they are good for the land as a rotational crop allowing the soil to rest and regenerate (they add nitrogen). From the 1970s, Australia’s annual chickpea crop has grown from virtually nothing to more than half a million tonnes. Award-winning food writer Carli Ratcliff explores this success story on the SBS Hunter-Gatherer blog and gives recipes for spinach-and-chickpea curry, chickpea salad and chickpea patties with mint raita. Check it out HERE.
#2 Cooking with Carisma Check out the results of a detailed taste test comparing the new general purpose low GI Carisma (GI 55) with the popular high GI Sebago (GI 87) on Catherine Saxelby’s Foodwatch website. Dietitian Josephine Mollica did the cooking and rates Carisma better than Sebago for boiling, mashing and dry baking but when it came to roasting, she found that although the Carisma was the more flavoursome, it didn’t crisp as well on the outside. Of course, when it comes to glycemic impact, the Carisma wins hands down. Read the review HERE – and keep those potato portions moderate!
#3 Bee Story Much of the food we put on our tables depends on pollination by honey and bumble bees which makes their decline a major concern. In the UK, bee colonies have doubled in six months due to amateur beekeepers harvesting honey. Martin Smith, president of the British Beekeepers’ Association, discusses whether it is the beginning of the end of the bee crisis HERE.
‘It’s very easy for all of us to do our bit for honeybees, bumblebees and other pollinating insects by growing the sort of plants and flowers they love – either in our gardens or in pots on windowsills or balconies. To have bees visit your garden is a cause for real celebration.’ – Kate Humble, Springwatch.
Professor Jennie Brand-Miller talks about her latest edition of the Low GI Diet Handbook … and how it all began and truly became a Glucose Revolution
Professor Jennie Brand-Miller
‘In 1995, I joined forces with Dr Stephen Colagiuri and Kaye Foster-Powell to write The GI Factor, the first book for the general public about the glycemic index of foods. Research on the glycemic index, or what became known as the GI, clearly showed that different carbohydrate foods had dramatically different effects on blood glucose levels. We believed that it was high time someone brought this story out to the general public. We knew from our own work that understanding the GI of foods made an enormous difference to the diet and lifestyle of people with diabetes. For some it meant, in our experience, a new lease of life.
In the early 1980s I was studying the nutritional composition of Aboriginal bush foods such as acacia seeds and cheeky yam. These foods are unique today because they are uncultivated foods, unlike wheat or potato. Food samples were sent from all over Australia to my laboratory at the University of Sydney for analysis and I took the opportunity to check the metabolic responses they created, that is, how they actually affected blood sugar levels in the body. The results were telling. Aboriginal bush foods produced only half the blood sugar responses of starchy Western staples like bread and potatoes. So, the question had to be asked: had these traditional foods somehow protected Aborigines from developing diabetes in times past? The answer was yes.
The GI of more than 2000 foods has now been tested worldwide, both singly and in combination with mixed meals. Long-term studies on its potential to improve diabetes control have also been carried out. We now know that consuming low GI foods is associated with a lower risk of both type 2 diabetes and coronary heart disease.
Our studies with animal models show that the GI of foods influences the rate at which animals gain body fat and develop abnormalities in insulin secretion. We have also tested the applications of GI for sporting performance and appetite control. It is now obvious, not only to us but to many expert committees and health authorities around the world, that the GI of foods has enormous implications for everybody. It is indeed a ‘Glucose Revolution’ in that it has changed forever the way we think about carbohydrates.
When our book was first published in 1996, we received a great deal of feedback from readers and health professionals. And still, hardly a day goes by without an email or letter from someone wanting to say thank you and to find out more. Now retitled the Low GI Diet Handbook (Hachette Australia), it brings together all the information that we have put together over the years to give you the most up-to-date and key dietary messages in one package. It will show you how the GI carbohydrate story fits in with all the other messages about fat, protein, exercise and the many ways you can approach having a healthy diet that suits you and your family’s lifestyle, no matter how busy you are. Most importantly the Low GI Diet Handbook focuses on individual needs, likes and dislikes and can be adapted to your particular eating habits and food preferences. Our Low GI Diet Handbook is not about one way of eating a healthy diet – it is about giving you the information to make eating a healthy diet much, much easier.
There’s not just one way of eating a healthy diet. What we now know about these different nutritional factors gives us a great deal of flexibility, which is extremely important and helpful in choosing food and food combinations that suit the likes and dislikes of you and your family.’
- Also available: Low GI Diet 12-week Weight-Loss Plan (Hachette Australia).
- Both titles can be purchased from good bookshops or online booksellers in Australia and New Zealand – e.book editions available soon.