GI Update with Prof Jennie Brand-Miller

Prof Jennie Brand-Miller answers your questions. 

I know that type 2 diabetes is one of the fastest growing chronic diseases worldwide. Do we know why this is so and what people like me (it runs in my family) can do to prevent getting it? 
The global increase in the prevalence of type 2 diabetes is being driven by the rise in overweight and obesity in all age groups. The reasons behind our weight gain creep are complex but include a simultaneous increase in global food abundance together with increased sedentariness and decreased physical activity during both work and possibly leisure time. Recent studies have also indicated that a deviation from the normal sleeping pattern of 7–8 hours sleep per night, particularly short duration of sleep, increases appetite and promotes obesity and its related diseases (e.g. type 2 diabetes and cardiovascular disease).

There are two ways to prevent type 2 diabetes: by preventing weight gain in the first place and by preventing people who already have pre-diabetes from progressing to diabetes with weight loss and maintenance. The main drivers in both situations are changes in dietary and physical activity patterns, but we also need to address disturbed sleep patterns and workplace stress. Unfortunately, despite convincing evidence from clinical trials that type 2 diabetes can be prevented or delayed through intensive lifestyle interventions resulting in weight loss, the reality is that weight regain and incremental weight ‘creep’ are very common. It is possible that this may jeopardise diabetes prevention and it remains to be seen the effect of a longer period of weight maintenance on prevention.

The recent Diogenes Study (Diet, Obesity and Genes) identified two dietary factors associated with shorter-term prevention of weight regain after prior weight loss: higher protein intake and lower glycaemic index (GI). The findings showed that overweight and obese participants assigned to the combination of modestly higher protein and lower GI ad libitum had significantly better completion rates and weight maintenance after six months as compared with the official dietary guidelines. Indeed, those consuming the high protein-low GI combination diet continued to lose weight during the weight maintenance phase and were twice as likely to have maintained a 5% weight loss compared to the other groups.

Here at the University of Sydney we are one of eight sites around the world taking part in the 3-year international PREVIEW Study. Its primary goal is to identify the most efficient lifestyle intervention pattern for the prevention of type 2 diabetes in people who are pre diabetic overweight or obese individuals (i.e. those at high risk of diabetes). The aim of this study is to find out the best methods (through diet, exercise and behavioural modification) of maintaining weight loss and keeping diabetes at bay. Individuals taking part in this study will have their own team of professionals dedicated to their weight loss and weight loss maintenance, all free of charge. We are recruiting participants now. If you are:

• Between the ages of 25–45 or 55–70 years 
• Overweight 
• Have a blood relative with diabetes 
• Been told you have pre-diabetes or impaired glucose tolerance you may be eligible to participate. 

This brochure will tell you about the study and how you can take part if you are eligible.

New GI Values from SUGiRS
Sustagen® Diabetic now has the GI Symbol 
Sustagen has been around a long time. It is a supplement designed for people finding it difficult to meet their nutritional requirements through regular food alone. There are a variety of products for specific purposes. Nestle Health Science have just launched Sustagen® Diabetic (vanilla flavour), specifically formulated to be low GI (34) for people with diabetes or pre-diabetes (type 1 or type 2) who are not eating well, or have a poor appetite, or are ill or recovering from illness. It provides essential nutrition without negatively impacting blood glucose levels. To be used under medical supervision.

• To make 1 serving, mix 7 level of scoops with 210ml water (or milk), stir and serve chilled or warmed (210ml is about ¾ cup).
• Nutrition information for 1 serving mixed with water: 25g carbohydrate and 8g fibre, 11g protein, 11g fat
• Glycemic load (GL) 1 serving = 3 
• For more information: www.sustagen.com.au 

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

Australia
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