FORMULA AND EXAMPLES TO CALCULATE AVAILABLE CARBS FROM THE GI & GL TABLE
Usually, the GI and GL tables are giving some parameters like glycemic index and glycemic load only but not the exact serving amount or portion of the food that represents the glycemic load.
For example, from the table, a medium-sized mango represents the glycemic (GL) 18.9 which is above normal (ie.>10) which a diabetic cannot take.
But if he knows the exact weight of that medium-size then he could reduce or cut down the weight of the mango to bring down the glycemic index to suit his need.
To eliminate such ambiguity in determining the size of the diet the following simple algebraic formula is very helpful.
Glycemic Load (GL)=[n x glycemic index(GI)]/100
where n-is the available sugar.
Hence by rearranging the above algebraic formula,
The available sugar (n) =[Glycemic Load x100]/GI
EXAMPLE-MEDIUM SIZED MANGO
Glycemic Index (GI) =56
Glycemic Load (GL) =18.9
Hence the active sugar =[GL/GI]x100
=[18.9/56]x100= 33.75gm
For 33.75gm the GL =18.9
For x-gm the GL =9 ; x=?
Proportionality equation =[18.9/33.75]=[9/x]
=[x x 18.9]=[9 x 33.75]
Hence x =[9 x 33.75]/18.9
=16.07gm
You can find out the amount of mango which contains 16gm active carbohydrates in google search.
A diabetic patient can consume mango up to 100gms which contains the sugar 13 to16gm in alternate days.
