Different types of carbohydrates in foods can affect the body in different ways. Net carbs reflect the amount of carbohydrates in a food that are likely to have an impact on blood glucose levels and can be a useful tool for athletes or anyone with specific nutritional goals.
It’s simple to determine the number of net carbs in a food by looking at the nutrition facts. Net carbs are calculated by subtracting the grams of fiber and sugar alcohols in a food from the grams of total carbohydrate as shown below:
Total Carbohydrate – Fiber – Sugar Alcohols = Net Carbs
Why calculate net carbs?
Carbohydrates are a group of compounds that are made up of carbon, hydrogen, and oxygen. Although different types of carbohydrates in food share similar chemical composition, each type has a distinct nutritional effect in the body. The grams of total carbohydrates that you see on a nutrition label include different nutrients such as sugar, starch, and fiber.
Sugar and starch are two types of carbohydrate that provide an essential source of energy. When you eat a food that contains these nutrients, the sugar and starch are digested, absorbed, and then transported through the blood stream in the form of glucose. This process results in a temporary increase in blood glucose levels. As the glucose is delivered to the body’s cells, the level of glucose in the blood stream falls, returning to normal. These sources of carbohydrate are considered most relevant to blood glucose levels and are the primary nutrients that are represented by net carbs.
See: Why Glycemic Index Matters for Your Appetite and Your Waistline
Dietary fiber is among the nutrients that make up total carbohydrate on a nutrition label. Unlike sugar and starch, fiber is a type of carbohydrate that is not digested or absorbed by the body and does not result in an increase in blood glucose levels. Fiber is certainly essential for digestive health, but it’s subtracted from total carbohydrate when calculating net carbs because it does not contribute to a rise in blood glucose levels.
Sugar alcohols, or polyols, are also counted as part of total carbohydrates on the nutrition facts label. They are found in fruits like apples, plums, and cherries and offer a naturally sweet taste. They don’t contain the type of alcohol that you would find in an alcoholic beverage. Their name only refers to aspects of their chemical structure. Sugar alcohols provide around half of the calories of other carbohydrates and won’t cause a rise in blood glucose levels. Since they don’t have the same effect in the body as sugar or starch, sugar alcohols are also subtracted from total carbohydrate when calculating net carbs.
What can net carbs tell you about a food?
Net carbs can give you an estimate of the amount of carbohydrate in a food that is likely to impact blood glucose levels. This can be especially helpful for anyone who has specific nutritional goals. Athletes, for example, may target a certain macronutrient range for carbohydrate, fat, and protein depending on the type and intensity of workouts in their training schedule. Calculating net carbs can help athletes meet these goals.
Since not all forms of carbohydrate have the same function in the body, calculating net carbs can help you get a sense of the amount of carbohydrate in a food that will influence blood glucose levels. Carbohydrates like dietary fiber and sugar alcohols don’t have the same nutritional functions as carbohydrates like sugar and starch. If you have specific nutritional goals or simply want to keep track of the amount of carbohydrate in your diet, calculating net carbs can help you identify the amount of carbohydrates that have the greatest impact.