If you are watching your carbohydrate intake, you might have heard of the concept of net carbohydrates. While this term has no official definition and can differ depending on who uses it, the general concept is that some forms of carbohydrates should be ignored since they pass through the body undigested. Understanding the concept of net carbs and how it impacts weight loss, blood sugar control and health can help you make wise carbohydrate choices.
Carbohydrates include sugars, starches and fiber in the diet. These components are generally found in grains, fruits, vegetables, beans, peas and dairy products. Carbohydrates have the largest impact on blood sugar levels of all of the macronutrients. Foods that are higher in sugars and starches tend to raise blood glucose significantly. This can have an effect on diabetes and on weight control in healthy individuals, since excess blood glucose gets stored in the body as fat. Fiber tends to keep blood sugar under control and can lower the blood sugar response of foods containing it. Fiber doesn't get digested by the body, but slows digestion of other foods consumed at the same time.
Net carbohydrates is not an official nutrition term and is not endorsed by the FDA or any other governing body. Some commercial diet programs use the term net carbs to refer to the total amount of carbohydrates minus the grams of fiber and sometimes minus sugar alcohols as well. Sugar alcohols are another form of carbohydrate that have an extremely small impact on blood sugar levels. For individuals who choose foods based on the blood glucose impact, calculating net carbs can be a useful technique.
Consuming adequate fiber helps keep your digestive tract working efficiently. Most adults should get between 20 and 35 g of fiber every day, but most people get only 10 to 15 g a day, according to Medline Plus. Fruits and whole grains are especially high in fiber. Being aware of the presence of fiber in foods makes it easier to figure out what the likely blood sugar impact will be. A piece of fruit with 15 g of carbohydrates and 5 g of fiber will have a much smaller impact than a spoon of 15 g of table sugar, which has no fiber.
While subtracting the fiber content from the total carbohydrate content of foods you eat can be helpful, subtracting the sugar alcohols might not be as useful. Sugar alcohols come in many different forms and some have more of a blood glucose impact than others. The sugar alcohols erythritol and mannitol are the only ones with no blood sugar impact, so subtracting these from the total carbohydrate amount might be of use.