Carbohydrates are made of many molecules of sugar. The simpler the food (things that are sugar or mostly sugar), the less your body needs to work at breaking it down and absorbing it. High fiber foods on the other hand, are difficult for your body to cut apart into glucose. So breaking these sugars in high fiber foods is a slower process than starches or sugars and it takes longer to raise glucose.
Calculate Net Carbs
Fiber is a carb that is indigestible, and doesn’t raise your glucose. To figure out how much of a food actually raises your blood sugars, subtract the fiber from the total carb to get net carbs. This is especially important for people needing tighter control of their blood sugars, like when they use a CGM device or take multiple daily insulin injections.