Fiber is important to any diet. Fiber is found in vegetables, fruits, beans, and whole grains. Fiber in food will slow the absorption of carbohydrates, but it is also considered a carbohydrate.
The general rule of thumb is that if food contains ≥5 g of dietary fiber per serving, subtract half the grams of dietary fiber from the total grams of carbohydrates. For example, if food contains 12 grams of carbohydrates and 6 grams of fiber, the amount of carbs that will affect your blood sugar is 9 grams.