What sugars do you subtract from carbs? Understanding Net Carbs

Did you know that not all carbohydrates are treated the same by your body, with some having minimal impact on blood sugar levels? For those tracking macros, especially on ketogenic or low-carb diets, understanding what sugars do you subtract from carbs is essential for an accurate net carb count.

Quick Summary

This guide explains the process of calculating net carbs by detailing which carbohydrate components are subtracted from the total, including fiber and specific sugar alcohols.

Key Points

• Net Carbs vs. Total Carbs: Net carbs are digestible carbs, while total carbs include both digestible and indigestible varieties like fiber.

• Subtract Only Indigestible Carbs: The grams of dietary fiber are subtracted completely from total carbs for an accurate net carb count.

• Handle Sugar Alcohols Carefully: Most sugar alcohols are partially absorbed, so only half of their grams are typically subtracted, but Erythritol can be fully subtracted.

• Never Subtract Standard Sugars: Natural and added sugars are fully digested and should always be counted toward your final net carb total.

• Consider the Source: Always read ingredient labels for sugar alcohols, as companies may have different definitions of 'net carbs' on their packaging.

• Whole Foods are Simplest: Whole foods with naturally high fiber content, like vegetables and legumes, are the easiest way to track net carbs without complex calculations.

Total Carbs vs. Net Carbs

On a nutritional label, the 'Total Carbohydrate' number represents all carbohydrate components in a food item, including starches, fiber, and sugars. However, not all of these are fully digested and converted into glucose. The concept of "net carbs" arose from the need to distinguish between digestible and indigestible carbohydrates. Net carbs are the carbohydrates that are fully absorbed by the body and impact blood sugar. The total carbohydrate value is not typically used for net carb calculations, especially on low-carb diets.

While the term "net carbs" is widely used within the health and fitness community, it's important to note that it does not have a legal definition from the Food and Drug Administration (FDA). The FDA recommends relying on the 'Total Carbohydrate' and 'Dietary Fiber' information provided on the label, especially for medical purposes like diabetes management.

What to Subtract and What to Leave

When determining the net carbohydrate value of a food, the process involves subtracting specific, non-digestible components from the total carbohydrates. It is a common misconception that all sugars are subtracted, but this is incorrect and would lead to inaccurate tracking of your intake.

Subtracting Dietary Fiber

Dietary fiber is a type of carbohydrate that is not broken down and absorbed by the body for energy. Instead, it passes through the digestive system largely intact. For this reason, the grams of dietary fiber listed on a nutrition label are fully subtracted from the total carbohydrate count to determine net carbs. Fiber intake is beneficial for digestive health and can help promote feelings of fullness.

Subtracting Sugar Alcohols

Sugar alcohols, also known as polyols, are another type of carbohydrate that is not fully digested. They are often used as sugar substitutes in processed foods labeled "sugar-free" or "no sugar added". However, the rules for subtracting sugar alcohols are not as straightforward as with fiber. Most sugar alcohols are only partially absorbed, so the general rule is to subtract only half of the grams listed.

There is a notable exception: Erythritol. This particular sugar alcohol is not absorbed by the body at all and can be fully subtracted from the total carbohydrate count. The partial digestion of other sugar alcohols like maltitol and sorbitol means they still have some impact on blood glucose, though less than regular sugar.

Here are some common sugar alcohols to look out for on ingredient lists:

• Erythritol
• Xylitol
• Sorbitol
• Maltitol
• Isomalt
• Lactitol
• Glycerol

Why You Don't Subtract Standard Sugars

The grams of total sugars and added sugars listed on the nutrition label are already included within the total carbohydrate number. These are considered fully digestible carbohydrates that your body breaks down and uses for energy, causing an increase in blood glucose and insulin levels. Therefore, you do not subtract them when calculating net carbs. The distinction between naturally occurring sugars (found in fruits and milk) and added sugars is important for overall health, as added sugars provide calories without additional nutrients, but they are both treated as digestible carbs for counting purposes.

Step-by-Step Guide to Calculating Net Carbs

1. Locate the Total Carbohydrate and Dietary Fiber on the food's nutrition facts panel. Note the serving size, as these numbers apply to a single serving.
2. Find the Sugar Alcohol content, which may be listed separately below the Total Carbohydrate count on products like candies or energy bars.
3. Subtract the fiber. Subtract the total grams of dietary fiber from the total carbohydrate count.
4. Subtract the sugar alcohols, following the specific rules: fully subtract Erythritol, and subtract half of all other sugar alcohols.
5. The Result is Your Net Carb Count.

Example Calculation: For a product with 20g of Total Carbs, 5g of Dietary Fiber, and 10g of Sugar Alcohols (not Erythritol), the calculation would be: 20g (Total Carbs) - 5g (Fiber) - 5g (half of Sugar Alcohols) = 10g Net Carbs.

Comparison of Carbohydrate Components

Component	Included in Total Carbs?	Is it Subtracted for Net Carbs?	Digestion & Blood Sugar Impact
Starch	Yes	No	Fully digested; raises blood sugar.
Natural Sugar	Yes	No	Fully digested; raises blood sugar.
Added Sugar	Yes	No	Fully digested; raises blood sugar.
Dietary Fiber	Yes	Yes (all grams)	Mostly indigestible; minimal blood sugar impact.
Most Sugar Alcohols	Yes	Yes (half the grams)	Partially digestible; moderate blood sugar impact.
Erythritol	Yes	Yes (all grams)	Not digestible; minimal blood sugar impact.

Conclusion

While the concept of net carbs is not officially regulated, it is a useful tool for those managing their carbohydrate intake, particularly for low-carb or ketogenic diets. The key is to correctly identify the specific, indigestible carbohydrate components—dietary fiber and select sugar alcohols—and subtract them from the total. Standard sugars, whether natural or added, should never be subtracted. For the most accurate tracking, always read the nutrition label carefully, pay attention to ingredients like sugar alcohols, and consider consulting a healthcare professional for personalized dietary advice, especially for medical conditions like diabetes. A balanced diet focusing on whole, unprocessed foods naturally provides fiber and allows for better health management.

What to subtract from carbs? Link

How to Calculate Net Carbs Step-by-Step

1. Locate the Total Carbohydrate and Dietary Fiber on the food's nutrition facts panel. Note the serving size, as these numbers apply to a single serving.
2. Find the Sugar Alcohol content, which may be listed separately below the Total Carbohydrate count on products like candies or energy bars.
3. Subtract the fiber. Subtract the total grams of dietary fiber from the total carbohydrate count.
4. Subtract the sugar alcohols, following the specific rules: fully subtract Erythritol, and subtract half of all other sugar alcohols.
5. The Result is Your Net Carb Count.

Frequently Asked Questions

What is the difference between natural sugars and added sugars in carb counting?

Both natural sugars (from fruit and milk) and added sugars (from syrups and processed ingredients) are fully digested carbohydrates that affect blood sugar. For carb counting, they are treated the same and are not subtracted when calculating net carbs.

Why don't I subtract all the sugar listed on the nutrition label?

The 'Total Sugars' value on a nutrition label includes all digestible sugars that are used by your body for energy. Since they contribute to blood sugar levels, they are part of your net carbohydrate count and should not be subtracted.

How do I calculate net carbs if a product contains both fiber and sugar alcohols?

To find the net carbs, subtract the total dietary fiber first. Then, subtract half of the sugar alcohols (unless it's Erythritol, which is fully subtracted). The final number is the net carb count.

Does the FDA recognize the term 'net carbs'?

No, the term 'net carbs' is not legally defined by the FDA. The FDA recommends focusing on the 'Total Carbohydrate' value for managing medical conditions like diabetes.

Why is Erythritol different from other sugar alcohols when calculating net carbs?

Unlike most sugar alcohols that are partially digested, Erythritol is not absorbed by the body. Because it has virtually no caloric or blood sugar impact, its total grams can be completely subtracted from the total carb count.

Can counting net carbs lead to digestive issues?

Yes, consuming large amounts of certain sugar alcohols can cause digestive side effects such as bloating, gas, and diarrhea because they are difficult for the body to digest.

Should someone with diabetes count net carbs or total carbs?

For diabetes management, the American Diabetes Association and FDA recommend focusing on the 'Total Carbohydrate' value. It is best to consult a healthcare provider or registered dietitian to determine the most effective carb counting method for your individual needs.