Dr Alan Barclay
Reduce that load and reduce your risk.
A-grade research (think Olympic gold level) from around the world over the past 20-plus years has shown pretty conclusively that type 2 diabetes is not caused by any single nutrient or food (such as sugar) but from a combination of diet and lifestyle risk factors.
The reason why there is no relationship between sugars and diabetes risk is simple: sugars only comprise about half of the carbs we eat, the other half comes from starches and both sugars and starches have a major impact on our blood glucose and insulin levels. So you can see that it makes no sense to focus on only one type of carbohydrate and ignore the other – especially as the GI values of both vary substantially. On the other hand, a systematic review we carried out in 2008 found those eating the highest GI diet had a 40% higher risk of type 2 diabetes than those with the lowest GI diet. Indeed, when it comes to pointing the finger at diet and diabetes risk, the strongest evidence to date is that it’s the overall glycemic load of your diet (i.e. the total amount of carbohydrate x GI) that’s the biggest potential problem.
The latest systematic review published on the topic provides a powerful addition to the evidence base. Researchers combined the results of 24 prospective cohort studies from around the globe, including 125,000 people, and found that high GL diets increased the risk of developing type 2 diabetes by 45%.
Like our 2008 systematic review the authors found that the validity of the tools used to assess peoples food and drink intakes had a significant effect on the strength of the association. If only the studies with the highest validity are included in prediction models, the association between GL and risk of type 2 diabetes increases to an enormous 105%.
This latest review also provides some very practical targets to help people reduce their risk of developing type 2 diabetes. They found that you need to ensure the average GL of your daily diet is less than 95 if you consume 8400kJ (2000 Calories) per day (the average intake for adults in developed countries). This can be achieved through a number of ways. For example, either consume:
FYI, 200g carbs would be roughly equivalent to eating a bowl of breakfast cereal with milk and a piece of fruit for breakfast (total ~45 g of carbohydrate), 2 slices of bread, a piece of fruit and a small tub of yoghurt for lunch (~60 g), a cup of cooked rice/pasta/noodles/etc... for dinner (~45 g), and fruit for dessert (~15 g) and 1 piece/glass/tub of fruit/milk/yoghurt (~15 g each) for inbetween meal snacks and/or supper.
- 200g carbohydrates a day with a GI of 50, or
- 225g carbohydrates a day with a GI of 45, or
- 250g carbohydrates a day with a GI of 40
We have found in our research that you actually don’t need to worry too much about counting carbs or GI. In fact you can achieve these targets by choosing moderate portions of low GI carbohydrates for most of your meals and snacks each day. Check out our simple tips for lowering the overall GI of your diet HERE.
The GI Symbol, making healthy low GI choices easy choices
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