Healthy Low Glycemic Foods |
Written by Toma Grubb | |
Friday, 17 August 2007 | |
Get most of your carbohydrates from low glycemic sources. This list of low glycemic carbohydrates is arrange with the lowest glycemic carbohydrates at the top of the list moving down to the higher glycemic carbohydrates at the bottom according to their GI rating. This list is culled from the Glycemic Index data base maintained by the University of Sydney in Sydney Australia. It is based on the work of Jennie Brand-Miller who is one of the world's leading authorities on the glycemic index. She and her co-authors have published a number of practical books on how choosing low GI carbohydrates. The books are available in our on-line Amazon store. Getting most if not all of your carbohydrates from low glycemic carbs in this list can help you maintain good glucose control.Measuring the GI 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. Does the GI increase with serving size? If I eat twice as much, does the GI double? 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. Why doesn't the GI of beef, chicken, fish, tofu, eggs, nuts, seeds, avocadoes, many fruits (including berries) and vegetables, wine, beer and spirits appear on the GI database? These foods contain no carbohydrate, or so little that their GI cannot be tested according to the standard methodology. Bear in mind that the GI is a measure of carbohydrate quality. Essentially, these types of foods, eaten alone, won't have much effect on your blood glucose levels. <!--[if gte vml 1]> |