Does anyone know the mathematics to calculate the Glycemic Index using a AUC Glucose/Blood curve? Is there an article documenting the process? I understand that algebra and integral calculus is involved.
I know the definition of the Glycemic Index is the relative rise in blood glucose level two hours after consuming food. It is the area under a 2 hours glucose/blood response curve, following a 12 hour fast and 50 g ingestion of a carbohydrate.
I know Glucose has a Glycemic Index of 100 and I'm unsure how this relates to the integral of (area under) the Glucose curve in the above graph. Also, the Glycemic Index appears to be unit-less, which is further confusing.
I try a rough calculation as follows and the results appear off. I draw a rectangle where the glucose curve is pictured here between 0-60 min, it comes out to 10 mmol/L - 6 mmol/L = 4 mmol/L y-axis, 60 min - 0 min = 60 min x-axis. The resulting area of the GI is 4 mmol/L * 60 min = 220 mmol/L * min and when the GI for Glucose should be 100.
Appreciate guidance here.