What are Net Carbs on a Keto Diet?

  • Date: June 10, 2022
  • Time to read: 6 min.
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You’ve probably heard of “net carbs.” It’s a term that you see on food packaging and menu items these days, especially for low-carb and keto-friendly foods. What are net carbs? And what is the difference between net carbs and total carbs? This is essential to know if you are going to succeed on a keto diet. Read on and all will be explained.

If you are following the ketogenic diet, you already know that keeping track of your carb intake is essential to your success in terms of weight loss and fat loss as well as an overall healthy lifestyle.

As a quick reminder, it is important to keep your net carbs under 20 grams of carbohydrates, in order to keep your body in ketosis and producing ketones and keep your energy levels high. This should account for around 5% of your total food consumption, with 70% coming from fat and 25% from protein. If you need to know more about this, check out this article as we won’t dwell on this here.

So what are net carbs and how do you calculate net carbs on a keto diet? First, you have to calculate your total carbs.

What is the difference between Total Carbs and Net Carbs?

If you’re striving to achieve ketosis, you probably already know that you should be cutting out carbs, but how do you decide what are “net carbs” and what are “total carbs”? The answer is simple, once you understand what you need to look out for. Let’s get started!

Total Carbs

The carb count in food can be confusing. So what are total carbs? In short, they’re a measurement of how much carbohydrate is in a serving of food. Carbohydrates are one of three macronutrients (think of these as the three main food groups). The other two macronutrients being, protein and fat.

When you look at a nutritional label on food it will list ‘Carbohydrates’ on their own, then sometimes it will break down more detail underneath; it’s those elements that make up the food group ‘carbohydrates’ that we are going to discuss now.

Dietary Fibre

Dietary fibre, more commonly known as ‘roughage,’ is a term for the parts of foods (normally plant-based foods) that are not broken down by enzymes in our bodies, and therefore not absorbed into the bloodstream.

It is bulky and high-fibre food that aids in the elimination of waste from the body promotes stable blood sugar levels and helps regulate cholesterol levels. This makes fibre essential in a healthy diet.

Sugar Alcohols

Sugar alcohols have a chemical structure that is similar to carbohydrates, but their molecules have a different arrangement, this prevents the body from completely breaking them down.

They are only partially absorbed unlike traditional granulated sugar, which is wholly absorbed. Instead, they are passed through the digestive system and expelled by the body as waste, also known as being ‘insoluble’.

This means that sugar alcohols are considered a “low-glycemic sweetener,” which means they won’t spike your blood sugar as quickly as traditional sugar.

Sugar alcohols are also called ‘polyols’.They have zero calories and can often be found in foods such as Skinny Syrups.

Polyols include Xylitol, Sorbitol, Erythritol, Isomalt, and Maltitol, just to name a few. They are popular sugar substitutes in keto-friendly foods such as sugar-free mints, sweets, and baked treats.

List of Polyols?

Polyols occur naturally in a lot of foods, like fruit and vegetables, or can be manmade. It is the manmade polyols that are added as low-calorie sweeteners to a lot of ‘diet’ foods, including keto foods.

The polyols that you need to be looking out for on your nutritional labels are;

  • Acesulfame K
  • Alitame
  • Aspartame
  • Brazzein
  • Curculin
  • Cyclamate
  • Erythritol
  • Glycerol
  • Glycyrrhizin
  • Inulin
  • Isomalt
  • Lactitol
  • Luo Han Guo
  • Mannitol
  • Miraculin
  • Monellin
  • Neotame
  • Oligofructose
  • Pentadin
  • Saccharin
  • Sorbitol
  • Stevia
  • Sucralose
  • Thaumatin
  • Xylitol
  • Yacon Syru

All of the above score a 5 or less on the Glycemic Index(GI), meaning they will not spike your blood pressure and therefore can be deducted in full from the total number of carbs listed on your nutritional label. 


There is always an exception, and this time Xylitol is it! Xylitol has a GI score of 12 (out of 100), which is still nowhere near as high as table sugar (granulated sugar), but as it is higher than the others, as such you only deduct half of the grams of Xylitol from your total carb count.

For sugar alcohols, deduct the grams of these from your total carb count EXCEPT Xylitol, only deduct HALF of the carbs from your total carb count.

How does the body process sugar alcohols?

It’s important to note that different people react in different ways to sugar alcohols. Some people experience side effects of bloating, gas and diarrhea, even when consumed in small amounts.

Keto sweets are the prime example of this, if you buy any sugar-free sweets, be careful as eating too many can soon have laxative effects.

Net Carbs

Net carbs are calculated by removing the dietary fiber grams and polyols from the total carb grams in a food.

How to Work Out Net Carbs

Food labels can be confusing, so we have broken this down for you, showing you what you need to look for in order to accurately work out your net carbs.

Please remember that not all products will have sugar alcohols (polyols) to deduct.

The formula looks like the below;

Check out the nutritional label below as a further example. In this case, the product did not have any of the sugars on the list above, therefore nothing further could be deducted;

Note that how to work out the net cars also works differs depending on the country you live in, we will explain this further below.

Do Net Carbs Change Depend on What Country I am in?

If you are living in the UK, EU or Australia, life is easier for you. The net carbs in your foods have already been worked out for you in part. The dietary fibre has been already been deducted for you. However, sugar alcohols have not.

You will need to check the ingredients if the ‘sugar’ in the product is one of the ones listed above, and there are no other sugars in the product, you will be able to deduct the number of grams of sugar from the total number of carbs listed (unless it is xylitol, in which case only deduct half the number of listed grams of sugar).

For labels on the USA and Canadian foods, fibre isn’t included in the total ‘Carbohydrate’ count, so our American and Canadian friends must deduct the fibre to get net carbs.

TOP TIP: If you are in doubt as to whether to deduct the sugars or not look at the spelling of fibre. In the UK, EU & Australia it is spelt ‘fibre’ in other counties it is spelt ‘fiber’. If it is the latter, it will be a good indication that you need to deduct the fiber.

Why Count Net Carbs rather than Total Carbs?

The science around the Keto Diet and Net Carbs is still fairly new, there are a number of studies ongoing around this.  Dr Stephen Phiney, who is one of the lead keto nutritionists suggests that you should only track total carbs. As you are not deducting fibre or sugars, Dr Phinney, suggests that keto dieters can eat up to 50 grams of total carbs a day and remain in ketosis.

Others argue that it is only the net carbs that should be counted, as this is the total amount of digestible carbs absorbed by the body.

The third school of thought is that people should only eat 20 grams of total carbs. This would be a very low-carb diet, and for most people, this would be far too restrictive. However, if you are using a keto diet in order to reverse a health condition such as diabetes, such strict carb restriction is something you may have to consider. 

For the vast majority of people, who are purely doing keto for the health benefits, 20 grams of net carbs consumed per day will be enough to keep them in nutritional ketosis and enjoy weight loss and change in body composition, without feeling too restrictive.

Personally, at Absolutely-Keto, we track net carbs only; all of our recipes are provided in net carbs. For us, this is the perfect balance of living a keto lifestyle and still being able to eat a small amount of fruit and vegetables.

Summary: What are Net Carbs?

Net carbs are the total amount of carbs, minus fibre and sugar alcohols. How you work these out, depends on what country you are eating in. There are different schools of thought on whether you should track, total carbs or net carbs; which you chose is up to you.

Let us know in the comments below what you track and the results that you have seen! ?

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