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]

1. Johanna Burani, MS, RD, CDE
www.EatGoodCarbs.com

2. 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).

3. Low 0-55
Moderate 56-69
High 70+

4.  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

5. (continued)
 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

6.  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.

7. Adapted from Good
Carbs Bad Carbs.
Reprinted courtesy of
Marlowe & Company.

8. Adapted from Good
Carbs Bad Carbs.
Reprinted courtesy of
Marlowe & Company.

9.  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.

10. • www.GlycemicIndex.com
• www.DavidMendosa.com
• Diabetes Care, Vol 31, No 12, December 2008

11.  www.EatGoodCarbs.com
 www.GlycemicIndex.com