What Are Net Carbs and Do They Actually Matter?
What Are Net Carbs and Do They Actually Matter?
Welcome to another entry in my series about carbohydrates and nutrition foundational information. At the end of this article, you can find links to earlier posts in this carbohydrate series for a better understanding of how carbohydrates actually work in the body.
If you have spent any time around popular diet trends over the last several years, you have likely heard the term “net carbs.” It appears frequently in low-carbohydrate and ketogenic diet spaces, on the front of package labeling, and in social media conversations about blood sugar, weight management, and, of course, the “keto” community. While the idea behind net carbs is easy to explain, it is important to be clear about what it is and what it is not.
Net carbs are not a formally recognized concept in nutrition science. They do not appear in the Dietary Guidelines for Americans (even in the newest 2025-2030 version), nutrition textbooks, or professional training for dietitians. That does not mean the idea is completely meaningless, but it does mean it should be approached with context and caution.
What Are Carbohydrates, Briefly
Before discussing net carbs, it helps to revisit what carbohydrates are. Carbohydrates are one of the three macronutrients, along with protein and fat. They are made up of three main components: starch, fiber, and sugar.
Read: What Are Carbohydrates? Fiber, Starch, and Sugar Explained
Starch and sugar are digested into glucose and used for energy. Fiber is also a carbohydrate, but humans cannot fully digest it. Some fibers pass through the digestive tract largely intact, while others are fermented by gut bacteria and produce beneficial compounds.
Read: Fiber 101: Soluble, Insoluble, Functional Fiber, and Resistant Starch
This distinction between digestible and nondigestible carbohydrates is the foundation for the net carbs concept.
What Are Net Carbs Supposed to Mean
Net carbs generally refer to the amount of carbohydrate in a food that is believed to affect blood sugar. The most common calculation looks like this:
Total carbohydrates minus fiber equals net carbs
or written another way
Total carbohydrate grams – fiber grams = “net carbs”
Some versions of the calculation also subtract sugar alcohols or certain types of added fiber. The reasoning is that fiber and some sugar alcohols do not raise blood glucose in the same way that starch and sugar do, so they should not be counted.
On paper, this sounds straightforward. In practice…? It becomes much less clear.
Where Did the Net Carbs Concept Come From
The concept of net carbs emerged largely from the low-carbohydrate diet movement, particularly during the resurgence of Atkins-style diets in the late 1990s and early 2000s. It gained traction because it allowed people to eat carbohydrate-rich foods while still staying within strict carbohydrate limits. Or, in my words, a “workaround” for eating carbs but still claiming it is low carb.
Food manufacturers quickly recognized the marketing potential – which they always do. They capitalize on what is trending among consumers, whether it is a legitimate, evidence-based concept or not. Products labeled as “low net carb” or “net carb friendly” began appearing on shelves, even though there was no standardized or regulated definition of the term.
This is an important point. Net carbs are not defined or regulated by the FDA. Different companies calculate them differently, and different diet programs apply different rules.
Why Net Carbs Are Not a Recognized Nutrition Concept
In nutrition science, we focus on measurable nutrients with defined physiological roles. Total carbohydrate, fiber, and added sugars all fall into this category. Net carbs do not.
There are several reasons for this:
First, not all fiber behaves the same way. Soluble fiber, insoluble fiber, functional fibers, and resistant starch all have different effects on digestion and metabolism. Assuming all fiber has zero impact is not accurate.
Second, sugar alcohols vary widely in their effects on blood sugar and digestion. Some have minimal effects, while others can raise blood glucose or cause significant gastrointestinal symptoms. Even if a sugar alcohol raises blood sugar, it will not raise it as much as other sugars.
Third, blood sugar responses vary between individuals. Two people can eat the same food and experience very different glucose responses based on insulin sensitivity, gut health, activity level, and overall diet pattern.
Because of this variability, a single net carb number cannot reliably predict physiological effects.
Do Net Carbs Matter for Blood Sugar
This is often the most common justification for using net carbs. For people with diabetes or insulin resistance, understanding how foods affect blood sugar is important. However, subtracting fiber from total carbohydrates is not a substitute for blood glucose monitoring, meal timing, or overall dietary quality.
Fiber can slow digestion and blunt or minimize blood sugar spikes, but it does not erase the carbohydrate content of a food. A food with a high total carbohydrate load can still significantly raise blood sugar, even if it contains fiber.
For people managing diabetes, consistent carbohydrate intake, portion awareness, and balanced meals are far more useful tools than net carb calculations.
Who Might Find the Concept Somewhat Useful
In limited contexts, the idea of net carbs can serve as a general reminder that fiber matters. Someone comparing two similar foods might notice that the option with more fiber tends to have a gentler impact on blood sugar or satiety.
However, this benefit comes from understanding fiber, not from relying on a net carb number. The same insight can be gained by looking at total carbohydrate, fiber, and ingredient quality together.
For most people, net carbs add unnecessary complexity without meaningful benefit.
Practical Concerns With Net Carb Counting
One of the biggest issues with net carbs is how they can distort food choices. Products marketed as low-net-carb are often highly processed and rely on added fibers, sugar alcohols, and refined ingredients. These foods may technically fit a net carb target but offer little in terms of overall nutrition.
Focusing on net carbs can also lead people to unnecessarily restrict fruits, whole grains, and legumes, all of which are associated with better long-term health outcomes.
Nutrition does not happen in isolation. We eat food, not numbers.
What Matters More Than Net Carbs
Rather than focusing on net carbs, a more useful approach is to look at overall dietary patterns. This includes:
Total carbohydrate intake that fits individual needs
Fiber intake from a variety of plant foods
Minimal reliance on ultra-processed products
Balanced meals that include protein, fat, and carbohydrates
Consistency over time
These are supported by decades of research and are reflected in national and international nutrition guidelines. This is not a new concept in 2026.
The Bottom Line
Net carbs are a concept created within diet culture, not nutrition science. While the idea attempts to account for fiber and digestion, it oversimplifies complex physiological processes and is applied inconsistently.
For most people, net carbs do not provide meaningful guidance and can distract from more important factors, such as food quality, fiber intake, and overall balance.
Carbohydrates include starch, fiber, and sugar. Fiber matters, but it does not cancel out carbohydrates. Understanding this distinction leads to better decisions than chasing a number that was never meant to be scientific in the first place.
Related blogs in this series:
Carbohydrates vs Sugar: What’s the Difference and Why It Matters
The Six Essential Nutrients Explained: A Foundational Guide to Nutrition
What Are Carbohydrates? Fiber, Starch, and Sugar Explained
Fiber 101: Soluble, Insoluble, Functional Fiber, and Resistant Starch
