Net carbs are the result of subtracting fiber and sugar alcohols from total carbohydrates. The concept behind them boils down to our body’s digestive processes.
Certain carbohydrates like fiber and sugar alcohols aren’t fully digested by the body or cause significant changes to blood sugar. When it comes to following the keto diet, they don’t have the same impact on ketosis and allow for more flexibility in your daily intake of carbs.
By tracking net carbs, you can manage your carb intake more effectively. This guide details why net carbs may be the way to go, how to calculate them, and their role in promoting weight loss.
Net Carbs Versus Total Carbs
Regular carbs, or total carbs, include the total amount of natural sugars, starches, fiber, and sugar alcohols in a product. Net carbs are what you’re left with after subtracting grams of fiber content and sugar alcohols from the total carbohydrates per serving.
Nutrition Facts labels list the total grams of carbohydrates per serving in a food. You can see if food manufacturers added large quantities of sugar alcohols to lower the net carbs of food or if your food has a significant amount of filling fiber.
Choosing to count total carbs instead of net carbs can be the easiest way to guarantee that you’re within your carb range for ketosis, but eating this way is much more restrictive.
The Role Of Fiber And Sugar Alcohols
The types of carbohydrates subtracted in the net carb formula include both fiber and sugar alcohols. Foods that are low in net carbs tend to be high in fiber, high in sugar alcohols, or a combination of both.
These low-impact carbohydrates are digested at a much slower rate. Due to this prolonged release of glucose into your bloodstream, insulin spikes are less likely to happen, resulting in sustained energy levels.
Fiber
While it won’t “cancel out” carbs, fiber doesn’t significantly impact blood sugar levels. This carbohydrate can’t be broken down into digestible sugar molecules and is fermented by the bacteria in your colon. Fiber is crucial for optimal metabolic and digestive system health. (1)
There are two main types of fiber: soluble and insoluble fiber.
Soluble fiber found in foods like fruit, legumes, whole grains, or dietary supplements can be diluted in water, creating a gel-like substance. It can make you feel fuller for longer, helping to promote weight loss. (2)
This happens because this substance slows down the process of absorption of food in the body. Even though it contains a small number of calories, it doesn’t seem to affect blood glucose levels. Soluble fiber also feeds your gut bacteria, ensuring a healthy microbiota. (3)
Insoluble fiber, on the other hand, does not dissolve in water, has no calories, and functions to help you have healthy and regular bowel movements.
When buying processed goods, reading nutrition labels is extremely important. Some manufacturers may include a type of processed fiber called isomaltooligosaccharide (IMO), often listed as tapioca fiber in ingredient lists.
IMOs can occur naturally in foods like honey or fermented foods, such as miso and soy sauce. When manufactured on a commercial scale, they’re processed from cereal crops like wheat, barley, oats, tapioca, rice, potato, pulses (e.g. peas, beans, lentils), and others.
Studies on IMOs show they may raise blood sugar levels. (4) Currently, the U.S. Food and Drug Administration (FDA) says there is insufficient evidence as to whether they benefit human health. The European Union prohibits health claims for oligosaccharides.
Sugar Alcohols
Sugar alcohols, also known as polyols, are made of sugar and alcohol molecules. They do not, however, contain ethanol, the compound that makes you intoxicated.
Sugar alcohols naturally occur in many fruits and vegetables, but they’re primarily used as alternative sweeteners. The most well-known ones are sorbitol, mannitol, erythritol, xylitol, and maltitol. They are commonly found in sugar-free foods.
Although they are considered alternatives to sugar, keep in mind that these polyols do contain calories and might affect your blood sugar and insulin levels. (5) It just won’t be to the extent of traditional sugars, and results vary by individual.
How to Calculate Net Carbohydrates
The formula to help you find grams of net carbs is: total carbs – (fiber + sugar alcohols).
If you’re a beginner at calculating net carbs, it is easiest to start by calculating them in whole foods. Whole foods consist of natural sugars and fiber without having to deal with sugar alcohols.
Take an avocado, for example. It’s one of the most important whole foods in a keto diet, not only for its dense nutrient content but also for the healthy fats it contains.
A medium avocado contains:
- 21g fat
- 2.7g protein
- 12g carbs, of which 9.2g is fiber
- 12g carbs – 9.2g fiber = 2.8g net carbs
Sugar alcohols can be a bit more difficult to calculate, as the calorie content of sugar alcohols differs. As a general rule, you can divide grams of sugar alcohols in half and subtract them from your total carbs. (Our guide to sugar alcohol goes into this in more detail.)
Reading the food label is a straightforward way to figure out the carbs in your diet, but apps and online tools can simplify the math.
Try our free Keto Calculator to help you find the exact amount of carbs, fat, and protein you need to reach (and maintain) your goal weight through the keto diet.
Why Net Carbs Matter
Net carbs are a reflection of the glycemic index (GI) of foods. (6) The GI of foods determines how quickly their carbohydrates are digested and enter the bloodstream. It is measured on a scale from 1 to 100, with 50g of glucose as the reference for a high-GI food.
Foods with a high GI are known as impact carbs. These foods, which include white bread, white rice, and sugary cereals, increase your blood sugar levels. (7)
When high-GI carbs enter your bloodstream — unless they’re immediately used for physical exercise — they typically contain more energy than your body can successfully use in one go.
Studies find that eating foods with large amounts of these carbs can affect metabolism and increase complications of chronic diseases like polycystic ovary syndrome (PCOS). (8) They may even increase the risk of certain cancers. (9)
On the other hand, foods that are low-GI tend to be higher in dietary fiber and more nutrient-dense compared to some high-GI foods. These include complex carbs found in foods like seeds, nuts, lentils, and many vegetables.
Guiding your food choices by net carbs can help you focus on getting your carbs from foods that have fiber and are likely to have other essential vitamins and minerals.
Blood Sugar Management
Net carbs represent the carbs that actively affect blood glucose. Low-GI or low-impact carbohydrates are digested at a much slower rate. Due to this prolonged release of glucose into your bloodstream, insulin spikes are less likely to happen, resulting in sustained energy levels.
For those with diabetes, controlling net carbs can reduce the need for insulin and improve glucose stability. This can mean improved diabetes outcomes with fewer blood sugar spikes and crashes. (10) It can also mean better metabolic health.
Weight Loss
In addition to monitoring calorie intake, choosing foods low in net carbs is important in supporting sustainable weight loss. (11)
The extra energy from high-GI carbs gets stored as glycogen in your muscles and liver or as body fat. Impact carbs can be very damaging to your health and waistline when you consume them regularly in high amounts. Foods high in impact carbs also tend to be lower in fiber.
Foods that are low in net carbs tend to stabilize blood sugars, reduce food cravings, and increase satiety to reduce overeating. Choosing whole foods that are naturally low in net carbs can also help you get the nutrients you need to support your metabolic health.
The keto diet is based on this system and is one of the reasons why it helps people lose weight.
Specific Dietary Needs
Net carbs are essential to a keto diet because they directly affect ketosis. To stay in ketosis, where the body burns fat for fuel, people typically limit carbs to 30-50 grams per day.
If you’re new to keto, it may feel easier to calculate total carbs to prevent getting out of ketosis, but counting net carbs may be the more sustainable option.
By tracking net carbs in keto over total carbs, keto dieters can enjoy nutrient-dense, fiber-rich foods without disrupting ketosis. This approach prevents excess restriction while still supporting your weight loss and health goals.For other dietary needs, tracking net carbohydrate intake can benefit anyone managing blood sugar or dieting for better cardiovascular outcomes. Net carbs can provide a more balanced approach to metabolic health.
The Bottom Line
Tracking your net carb count is a great way to make smart choices about the carbs you eat and to maximize your intake of fiber for a healthy metabolism. You can use this information to integrate low-net-carb foods into your daily diet and form a plan that will keep you in ketosis.
Completely eliminating any nutrient from your diet is never the best way to ensure overall vitality. A balanced approach to your macros, especially if you’re very physically active, is the key to meeting your nutritional needs.
The main goal of a low-carb diet like a ketogenic diet is to replace most carbs with healthy fats and protein, but it’s also important to know how to most effectively use your carbohydrates. Whether you track net carbs or total carbs on keto depends on your dietary needs and goals.
To learn more about using keto to help you make that happen, sign up for our Keto Kickstart, a 30-day, step-by-step guide to keto, its health benefits, and getting the results you want.
Read Next: Is Milk Low-Carb? Carbs in Milk and Keto Alternatives
FAQ
What foods have zero net carbs?
Foods with zero net carbs include zero-carb foods. These are most animal-based products like meat, poultry, fish, and eggs, as they contain protein and fat without carbohydrates. Certain oils and fats, such as olive oil, coconut oil, and grass-fed butter, also have zero carbs. Leafy greens, a healthy addition to a keto diet, have very low or negligible net carbs.
Is the keto diet dangerous?
In most cases, keto and ketosis are safe and beneficial for the prevention and management of metabolic health conditions and potential weight loss. In the short term, however, they can cause initial side effects like fatigue or the “keto flu.”
It’s important to talk to your healthcare provider or a registered dietitian before starting any new diet like keto so that you’re well-equipped to monitor relevant health markers. This is especially important if you’re managing a condition like type 2 diabetes or obesity.