The glycemic index or GI is a scientifically researched and validated tool that places foods and beverages on a scale of 1-100. About two thousand food items have been tested to date.
The idea behind glycemic indexing comes from the fact that all food and drink that you consume has an effect...from virtually nothing to extreme...on your blood sugar level (blood glucose level) and a corresponding rise in your blood insulin level.
If a food's GI is 100 on the index then it has been shown to produce a rapid blood sugar level and insulin response in test subjects. If a food is at 1 on the GI index, its effect on blood sugar is negligible.
Heart disease and weight loss:
There is a powerful scientifically validated link between having an abnormally elevated blood insulin level and the development of coronary artery disease risk factors, atherosclerosis, weight gain and fat loss.
Having a high insulin level promotes abnormally high blood fats...that's your cholesterol and triglyceride levels...along with high blood pressure and a strong tendency to store excess food energy as fat.
Your pancreas also comes under a significant amount of stress as it works to meet the insulin demands placed on it as a direct result of your food choices.
It makes a lot of sense to moderate (not eliminate...balance is important) your carbohydrate intake...especially those carbohydrates that are quickly absorbed and stimulate a fast release of insulin from your pancreas.
Low glycemic carbohydrates encourage a more even and moderate insulin response in most people and tend to leave you feeling satisfied (satiety) for longer.
Foods on the GI have been tested for their speed or response time to show up as carbohydrate - that is...simple or complex sugar molecules in the blood stream.
What types of foods have been GI Indexed?
The GI is the result of testing real foods on real test volunteers. some foods containing lots of carbohydrates that absorb quickly and others containing little or none at all.
Both natural foods such as vegetables, legumes, fruit...and processed, packaged name brand foods have been tested by analyzing blood samples of the test subjects.
Is Low Carb low GI?
Just because a food is a low carbohydrate food doesn't necessarily mean that it is a low GI food. The small amount and type of carbohydrate that it does contain might still cause a rapid rise in your blood sugar and insulin response. Low GI foods contain carbohydrates that absorb slowly producing a more gentle blood sugar and insulin response.
The low GI diet:
The glycemic index diet is the name given to the daily consumption of foods that have been tested for their low GI so that you can be assured that what you are eating is in fact low GI.
GI indexing is scientifically validated:
Globally, testing laboratories that assess food items for their glycemic response in humans are available in Canada, United Kingdom, France, Netherlands, Finland, Australia and New Zealand. They all use a standardized scientific method for their glycemic index evaluations.
Although the concept of glycemic-indexing is Canadian in origin, introduced by Dr David Jenkins currently a profesor of nutritional sciences at the University of Toronto...a great deal of research and published information now comes from the University of Sydney in Australia with Professor Jennie Brand Miller and her colleagues Kaye Foster Powell and Professor Stephen Colagiuri contributing hugely to the science behind the glycemic index concept.
In the latest book on the subject of the low glycemic index diet principle by Jennie Brand Miller and her colleagues called The Low GI Handbook there is a very interesting quote from the Journal of the American College of Cardiology
Here it is...
"...it is time to shift the diet-heart paradigm away from restricted fat intake and toward reduced glycemic load. (This)should be considered a public health priority."
- Professor Frank Hu, Journal of the American College of Cardiology, July 2007.