Hi budgiemom, Good question. The glycemic index is fixed regardless of portion size. The 50 grams of carbs is just the amount they use for the test. And you’re right the NC and DF vary as expected with serving size.
I estimate one (57g) Trader Joe’s rice tortilla (the only one I can find nutritional facts for is the “brown” rice tortilla) as having an FP of 14 grams. Note: I used a conservative estimated glycemic index of 50 for the calculation since the rice used is likely not a high GI variety. That gave 12 grams. Then I added the two fiber grams.
Reply To: Calculating FPNorm Robillard2014-03-07T21:16:49-04:00