What are net carbs? Whether you’re following the keto diet, going low-carb, or simply want to understand food labels better, this may be a question on your mind. As a nutritionist, I have worked with many clients who wanted to better understand the components of the food they are eating, as we aren’t always taught much beyond what a carbohydrate is in the first place.
Keep reading to learn more about net carbs, how to calculate them, and why you may want to track them!
What are net carbs?
Net carbs essentially refer to the amount of carbs that directly impact your blood sugar levels, as they are digestible and absorbed by the body. According to the American Diabetes Association, “Net carbs are determined by subtracting any fiber or sugar alcohols on the label from the total carbohydrates.”
The concept of net carbs is particularly popular among people following low-carb or ketogenic diets, who want to manage their carbohydrate intake more precisely. By subtracting fiber and certain sugar alcohols from the total carbohydrates, net carbs provide a clearer picture of how many carbs will affect your metabolism and energy levels.
One way to think of it is that net carbs represent the “usable” carbs that your body can convert into glucose. Understanding net carbs can help with better blood sugar control, weight management, and staying in a state of ketosis for those on keto diets.
How to calculate net carbs
As we mentioned before, calculating net carbs is straightforward once you know what to look for on nutrition labels. The basic formula subtracts fiber and certain sugar alcohols from the total carbohydrates because these don’t significantly affect blood sugar.
To calculate net carbs, follow these steps:
- Find the total number of grams of carbohydrates listed on the nutrition label.
- Subtract the number of grams of dietary fiber since fiber isn’t digested or absorbed.
- Subtract the number of grams of sugar alcohols present on the label. Many foods won’t contain any sugar alcohols.
For example, if a food has 20 grams of total carbs, 8 grams of fiber, and 4 grams of erythritol, the net carbs would be 8 grams (20 – 8 – 4 = 8).
Keep in mind that labels may vary, and some manufacturers already list net carbs separately. It’s important to read ingredient lists to understand which sugar alcohols are included as well.
Why should you track your net carbs?
Tracking net carbs helps many people manage their blood sugar levels and overall carbohydrate intake more precisely. Unlike total carbs, net carbs focus on the digestible carbs that actually affect your blood glucose, making it easier to avoid spikes that can impact energy and hunger.
For those following low-carb or ketogenic diets, tracking net carbs is essential to stay within daily limits that promote fat burning and ketosis. It allows greater flexibility by recognizing that not all carbs are equal — fiber and some sugar alcohols don’t count toward carb limits.
Additionally, paying attention to net carbs can support weight management by helping you make smarter food choices that reduce unnecessary carbohydrate intake without cutting out nutrient-rich fiber.
Overall, tracking net carbs provides a clearer understanding of how your diet affects your body and helps tailor eating habits to meet specific health or fitness goals.
Common mistakes made when counting net carbs
One common mistake made when counting net carbs is failing to subtract all the fiber correctly. Some people forget that all dietary fiber should be subtracted because it doesn’t raise blood sugar, while others may only subtract soluble fiber and not insoluble, leading to inaccurate counts.
Another frequent error involves sugar alcohols. Not all sugar alcohols impact blood sugar in the same way. For example, erythritol can be fully subtracted because it has little to no effect on blood glucose. However, maltitol raises blood sugar more significantly and should only be partially subtracted — typically, you should count about half of the grams of maltitol as net carbs. Failing to account for these differences can lead to inaccurate tracking and miscalculations.
Relying solely on nutrition labels without checking ingredient lists can also lead to mistakes. Some manufacturers list net carbs directly, but not all do, and hidden carbs might be overlooked.
Lastly, some people underestimate portion sizes, counting net carbs for less than they actually eat, which can affect blood sugar and diet goals. Paying close attention to servings is essential for accurate tracking.
Frequently asked questions
Should I count carbs or net carbs?
Counting net carbs is often more useful for people managing blood sugar or following low-carb diets, as it focuses on digestible carbs that impact your body. However, counting total carbs may be better for those needing strict carb control, like diabetics or athletes with specific nutrition goals.
What is the worst carb for belly fat?
Refined carbs like sugary drinks, white bread, and pastries are often considered the worst for belly fat. They cause rapid blood sugar spikes and increased insulin levels, promoting fat storage around the abdomen. Limiting these processed carbs can help reduce belly fat over time and improve your general health.
Does fiber really cancel out carbs?
Fiber doesn’t exactly “cancel out” carbs, but it isn’t digested or absorbed like other carbs, so it doesn’t raise blood sugar. That’s why fiber is subtracted when calculating net carbs. However, fiber still provides important health benefits like improving digestion and supporting gut health.
