glycemic index international testing protocol - johanna burani, ms, rd, cde
DESCRIPTION
Why does the World Health Organization only endorse one protocol for international glycemic index (GI) testing? Johanna Burani, MS, RD, CDE explains the intrinsic difference between WHO and other protocols being used in the marketplace. [Also available with narration at http://www.EatGoodCarbs.com]TRANSCRIPT
Johanna Burani, MS, RD, CDE
www.EatGoodCarbs.com
It is a scale from 0-100 that ranks digested carbohydrates by how much they raise blood glucose levels compared to a reference food (glucose).
Low 0-55
Moderate 56-69
High 70+
10 healthy, fasting volunteers
25-50 g available carbohydrate of test food
25-50 g reference food (glucose)
Blood samples taken at 15-30-minute intervals over the next 2 hours
Values plotted for 1 test food trial and the averaged 3 reference food trials
Area under each curve (test food and reference food average) calculated and compared for each volunteer
Average of the comparisons (GI ratings) from all 10 volunteers = GI value for the test food
(continued)
For each subject: participation in 1 test food trial and 3 reference food trials; individual’s test food response is compared to the average of his/her 3 reference food responses.
For all 10 subjects: the average calculated from these 10 comparative responses becomes the GI value for the test food.
Adapted from Good Carbs Bad Carbs.
Reprinted courtesy of Marlowe & Company.
Adapted from Good Carbs Bad Carbs.
Reprinted courtesy of Marlowe & Company.
Accounts for intra/inter-metabolic variability from day to day.
Comparing test food responses to averaged glucose responses manages this variability.
Generates 320 or more data points.
• www.GlycemicIndex.com
• www.DavidMendosa.com
• Diabetes Care, Vol 31, No 12, December 2008
www.EatGoodCarbs.com
www.GlycemicIndex.com