What is GI?GI is stand for Glycemic Index or Glycaemic Index.A concept that was developed by Dr. David J. Jenkins and colleagues in 1980 - 1981 at University of Toronto to identify which food or to categorized it for people with diabetes problem.GI were used to measure the effect of carbohydrates on blood glucose levels.
Whats the different between low and high GI?When human body break down the carbohydrates in digestion process,if the carbs break down and releasing glucose rapidly into the bloodstream it is called high GI level.Meanwhile if the carbs break down slowly,it is called low GI level.
How they measuring the GI level?According to the method used by University of Sydney, to determine a food's GI rating, measured portions of the food containing 10 - 50 grams of carbohydrate are fed to 10 healthy people after an overnight fast. Finger-prick blood samples are taken at 15-30 minute intervals over the next two hours. These blood samples are used to construct a blood sugar response curve for the two hour period. The area under the curve (AUC) is calculated to reflect the total rise in blood glucose levels after eating the test food. The GI rating (%) is calculated by dividing the AUC for the test food by the AUC for the reference food (same amount of glucose) and multiplying by 100 (see Figure 1). The use of a standard food is essential for reducing the confounding influence of differences in the physical characteristics of the subjects. The average of the GI ratings from all ten subjects is published as the GI of that food.
What are the benefits of Glycemic Index to us?After understands what is the GI stand for,we should now know that having a low GI food will help our body to maintain its energy last longer.Here are more benefit we will get for obtains these type of food:
- Low GI carbs prolong physical endurance
- Low GI carbs reduce hunger and keep you fuller for longer
- Low GI carbs reduce blood cholesterol levels
- Low GI carbs reduce the risk of heart disease
- Low GI carbs improve diabetes control
- Low GI diets increase the body's sensitivity to insulin
- Low GI diets help people lose and control weight
Does the GI increase with serving size?The GI always remains the same, even if you double the amount of carbohydrate in your meal. This is because the GI is a relative ranking of foods containing the "same amount" of carbohydrate. But if you double the amount of food you eat, you should expect to see a higher blood glucose response - ie, your glucose levels will reach a higher peak and take longer to return to baseline compared with a normal serve.
Is a low GI diet suitable for vegetarians?The range of protein and carb intake that is healthy is fairly broad - as a vegetarian you will inevitable have a higher carb intake and slightly lower protein intake. This makes the GI important for you but easy to adapt if you choose wholegrain cereal products and legumes as your carbohydrate base.The GI only applies to foods containing significant amounts of carbohydrate. Most vegetables have small amounts of carbohydrate and those that provide more usually have a low GI, with the exception of potatoes. You can therefore tuck into your veggies without considering the GI for every one.