- Norm RobillardKeymasterFebruary 6, 2014 at 10:58 pmPost count: 445
No problem : ) It’s pretty low which is great! Thanks for providing the nutritional facts Greer.GreerParticipantFebruary 6, 2014 at 11:08 pmPost count: 17
OK thanks- I was not too far out at 1.8 gm / 100 g But 1.3 is even better.
May have found my energy supplement! only a little seems to have a benefit too.KellyParticipantMay 12, 2014 at 10:46 pmPost count: 77
Norm, I saw above where you calculated the FP, and I’m a bit confused on how it works. Following the formula (100-GI)/100 * NC + fiber + SA: I did (100-GI)/100 * grams of sucrose/fructose and added them to get 1.23. Close to your answer but either I did something wrong or there’s a difference because of rounding. I don’t quite get how the total carbs works into that since there’s no fiber.
Then I tried doing a weighted average of GI * % of each sugar, and using that as GI in the formula with the total carbs. Which gave me 1.37, which is also a little off. So I’m stumped.
(I’m not asking just to be pedantic — I’m wondering if it’s possible to do this with other foods when the total GI isn’t available.)Norm RobillardKeymasterMay 13, 2014 at 4:11 pmPost count: 445
Hey Kelly, Good I have you all here to check my math! I did the calculation again and got 1.45g. Let’s go through it together this time.
There are 1.64 grams of sucrose (GI is 59). FP = (100-59)(1.64)/100 = 0.67 g
There are 0.71 grams of Fructose (GI is 20). FP = (100-20)(0.71)/100 = 0.57 g
There are 2.35 grams of glucose (GI is 100). FP = 100-100(2.35)/100 = 0.0 g
There are 0.49 grams of non sugar starch (5.2 total carbs minus 4.71 grams of sugars). For this I estimated a GI of 58 (approximation for starches). FP = (100-58)(0.49)/100 = 0.25 g (I might have forgotten to add this last time).
Final FP = 0.67 + 0.57 + 0.0 + 0.25 = 1.49 grams.KellyParticipantMay 13, 2014 at 5:30 pmPost count: 77
Thanks for the explanation Norm, that makes more sense. Is it possible to do this for any food when the GI is unavailable, or is it only because this is essentially sugar?
If so: You estimated the GI of starch at 58. If you knew the breakdown of amylopectin vs. amylose, how would you work that in?Norm RobillardKeymasterMay 13, 2014 at 6:16 pmPost count: 445
If you know the exact ratio of amylose/amylopectin, you could assign amylopectin foods a GI = 98-100 and amylose foods as GI 0 (really more of a dietary fiber). When you don’t have the glycemic index, the best approach is to estimate the GI based on similar foods. Most foods that contain amylose usually have about 20-30 percent of their starch in this form, with the rest being amylopectin. The GI of these foods range from about 40 – 70 with lower GIs associated with more amylose. If I don’t know the amylose content of a starch, I just use something like 58 which is typical for amylose-containing rices. If you want to be the most conservative, you can always just count all the carbs as FP when you don’t have a GI, but in reality, the FPs would not be that high.
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