Does carbohydrate include fiber? The answer is yes… and no! It depends on where you live.
By the dictionary definition, carbohydrate is chemically composed of carbon, hydrogen, and oxygen and is generally made up of sugars, starch, and fiber. When carbohydrate is listed in food composition tables, or on Nutrition Facts panels, however, there are several international standard definitions that can be used. These definitions determine which components (sugars, starch, fiber, other) are included in the carbohydrate total.
Carbohydrate by Subtraction
In the United States, carbohydrate is defined as “carbohydrate by subtraction”. This means that when a food is chemically analyzed in a lab, the grams of protein, fat, alcohol, water, and ash are subtracted from the total gram weight of the sample, and the amount left over is considered the carbohydrate value. Using this method, the carbohydrate value contains sugars, starch, and fiber, and may also contain small amounts of other compounds that do not fit specifically in one of the other assays. This carbohydrate definition is used in food composition tables and for nutrition labeling in the U.S. and Canada.
For nutrition labeling in the EU and Mexico, however, carbohydrate is defined as “available carbohydrate”, which does not include the fiber component. This value is determined by adding up the sugars and starches in the sample.
For accurate international nutrition labeling, Genesis R&D Food Formulation & Nutrition Labeling Software accommodates fields for both of these carbohydrate definitions and links them with the appropriate nutrition labeling module. Whether or not fiber is included in the carbohydrate total and the calorie calculation can have a big impact on the label calories reported.
Below you can see a fruit salad recipe in both the U.S. Standard Nutrition Facts Label format and in the EU Nutrition Information Label format. The U.S. label uses 4 calories per gram to calculate the total carbohydrate value (which includes the fiber). The EU label uses 4 calories per gram for the carbohydrate value (available carbohydrate) and 2 calories per gram for the fiber value.
Notice the difference in reported carbohydrate and calories.