Calculating Net Carbs For Keto: A Step-By-Step Guide

Net carbs are the number of carbohydrates that are absorbed by the body and used for energy. They are calculated by subtracting the amount of fibre and sugar alcohol from the total number of carbohydrates. This calculation is important for people on the keto diet as it helps them stay in ketosis, a metabolic state where the body burns fat for fuel instead of carbohydrates.

Net carbs are the carbs absorbed by your body

When you eat a carb-containing food, most of the carbs are broken down into individual sugar units by enzymes produced in your small intestine. Your body can only absorb these individual sugar units. However, some carbs can't be broken down into individual sugars, while others are only partially broken down and absorbed. These include fiber and sugar alcohols, which are not absorbed by the body and, therefore, do not impact blood sugar or insulin levels.

To calculate net carbs in whole foods, you subtract the fiber content from the total number of carbs. For processed foods, you also need to subtract half of the sugar alcohol content from the total number of carbs.

For example, let's say you're looking at a nutrition label for a food product. The label states that the product contains 13 grams of total carbohydrates, 9 grams of fiber, 2 grams of erythritol (a type of sugar alcohol), and 1 gram of allulose (another type of sugar alcohol). To calculate the net carbs, you would subtract the fiber and half of the sugar alcohol content from the total carbohydrates:

13g (total carbs) - 9g (fiber) - 1g (erythritol) - 0.5g (allulose) = 2.5g net carbs.

It's important to note that the Food and Drug Administration (FDA) does not recognize the term "net carbs" and recommends using the total carbohydrates listed on nutrition labels. Additionally, the calculation of net carbs can vary depending on the type of sugar alcohol present and whether the food is a whole food or a processed food.

Total carbs include fibre and sugar alcohols

Total carbohydrates refer to starch, fiber, and sugar. When purchasing packaged food, the term "total carbohydrates" refers to all three of these types. On a nutrition label, starches are not listed separately, but they are the remaining carbs that are not any of the other types.

Sugar alcohols are neither a sugar nor an alcohol. They are a type of carbohydrate that simulates sweetness. They are often found in sugar-free or no-sugar-added products.

Net carbs are calculated by subtracting the fiber content and sugar alcohols from the total carbohydrates. This is because fiber and sugar alcohols are not absorbed or metabolized by the body in the same way that other carbohydrates are.

> NET CARBS = TOTAL CARBS – FIBER – SUGAR ALCOHOLS & ALLULOSE

For example, a food with 13 grams of total carbohydrates, 9 grams of fiber, 2 grams of erythritol, and 1 gram of allulose would have 1 gram of net carbohydrates.

The Food and Drug Administration (FDA) does not recognize the term "net carbs" and recommends using total carbohydrates listed on nutrition labels.

Net carbs are calculated differently for whole and processed foods

Whole Foods

Whole foods contain naturally occurring fibre. To calculate net carbs in whole foods, you simply subtract the fibre from the total number of carbs. For example, a medium avocado contains 17.1 grams of total carbs, 13.5 grams of which is fibre. So, 17.1 grams of total carbs minus 13.5 grams of fibre equals 3.6 grams of net carbs.

Processed Foods

To calculate the net carbs in a packaged product, the more information you have, the better. Generally speaking, half of the carbs from sugar alcohols can be subtracted from the total carbs listed on the nutrition label. Erythritol is an exception. If it's the only sugar alcohol in the ingredients list, its carbs can be completely subtracted from the total carbs.

For example, a maltitol-sweetened Atkins bar label states that it contains 3 grams of net carbs. However, when subtracting only half the carbs from sugar alcohols, the net carb value is 8.5 grams: 23 grams of total carbs minus 9 grams of fibre minus 11 grams of sugar alcohols (11 grams multiplied by 0.5 equals 5.5 grams) equals 8.5 grams of net carbs.

Net carbs are important for keto dieters to know which foods to eat

Net Carbs: A Crucial Consideration for Keto Dieters

The ketogenic (keto) diet is a popular nutritional approach that involves significantly restricting carbohydrate intake and replacing those calories with fat. This shift in macronutrient ratios pushes the body into a metabolic state called ketosis, where fat becomes the primary energy source instead of carbohydrates. To achieve and maintain ketosis, it is essential for keto dieters to understand and monitor their carbohydrate intake, specifically focusing on net carbs.

Net carbs refer to the carbohydrates that are absorbed by the body and used for energy production. These include simple carbs, such as sugars, and complex carbs, like starches. Net carbs are calculated by subtracting indigestible components, such as fiber and certain sugar alcohols, from the total carbohydrate content of a food item. This distinction is crucial because fiber and some sugar alcohols pass through the digestive system without being broken down or absorbed, and therefore do not impact blood sugar levels or insulin response.

Keto dieters need to limit their daily carbohydrate intake to approximately 50 grams or less to induce and sustain ketosis. Net carbs provide a more accurate representation of the carbohydrates that can potentially disrupt this metabolic state. By considering net carbs, keto dieters can make more informed food choices and include a wider variety of nutritious options in their diet.

How to Calculate Net Carbs

Determining net carbs is a straightforward two-step process. First, identify the total carbohydrate content of a food item by reading the nutrition label. Second, subtract the grams of fiber and sugar alcohols from the total carbohydrates to calculate the net carb count. It is important to note that not all sugar alcohols are treated equally; some have a more significant impact on blood sugar and should be factored into the net carb calculation.

Net Carbs in Practice

Let's consider an example to illustrate the impact of net carbs on food choices. A medium avocado is a nutritious option but also contains 17.1 grams of total carbohydrates, which may seem high for a keto diet. However, avocados are rich in fiber, with 13.5 grams per medium fruit. By subtracting the fiber content, we find that the net carbs in a medium avocado are only 3.6 grams, making it a keto-friendly choice.

In conclusion, understanding and calculating net carbs is a valuable tool for keto dieters. It allows them to make informed decisions about their food choices, ensuring they stay within their carbohydrate limits while also incorporating a variety of nutritious, fiber-rich foods into their diet. By focusing on net carbs, keto dieters can better manage their blood sugar, maintain ketosis, and enjoy the benefits of this dietary approach.

Sugar alcohols are not always subtracted from total carbs

Sugar alcohols are often subtracted from total carbs to calculate net carbs because they have a minimal impact on blood sugar levels compared to regular sugar. However, not all sugar alcohols are created equal, and their effects on blood sugar levels vary. For example, erythritol has virtually no impact on blood sugar levels, while maltitol can significantly raise them.

Due to these varying effects, some experts argue that not all sugar alcohols should be treated equally when calculating net carbs. They suggest that sugar alcohols like maltitol, xylitol, and sorbitol should not be fully subtracted from total carbs because they can still impact blood glucose levels, albeit to a lesser extent than regular sugar.

As a result, the general rule of thumb is to subtract half of the sugar alcohol content from the total carbs when calculating net carbs for processed foods. Erythritol is an exception, and its carbs can be completely subtracted from the total if it is the only sugar alcohol in the ingredients list.

It's important to note that the keto diet limits net carbs to 20 grams per day, not 20 grams of total carbs. Therefore, understanding how to read food labels and correctly calculate net carbs for sugar alcohols is crucial for staying within the recommended daily limit.

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