What Are Net Carbs Anyway?

Net carbs, also known as "impact carbs" or "active carbs", have become increasingly popular to track, especially among those following low-carb or ketogenic diets. But what exactly are net carbs and should you be focusing on them?

Net carbs are calculated by subtracting the grams of dietary fiber and sugar alcohols from the total carbohydrates in a food. The idea is that since fiber and certain sugar alcohols like erythritol and xylitol are not fully digested and absorbed by the body, they don't "count" toward the total carbohydrates that impact blood sugar and are used for energy.

For example, if a protein bar has 15 grams of total carbs, 9 grams of fiber, and 2 grams of erythritol, the net carbs would be 4 grams (15g - 9g - 2g = 4g net carbs).

Benefits of Tracking Net Carbs

There are a few potential benefits to paying attention to net carbs:

• May help with blood sugar control, especially for diabetics. Since fiber doesn't raise blood sugar, basing insulin dosage on net carbs rather than total carbs reduces the risk of low blood sugar.
• Allows for consumption of more high-fiber foods while still limiting overall carbohydrate intake. This can be useful for those on strict low-carb diets.
• Simple calculation to do. Just subtract fiber and certain sugar alcohols from total carbs.

Downsides of Focusing on Net Carbs

However, there are also some significant drawbacks to relying too heavily on net carbs:

• Not all fibers and sugar alcohols are truly "carb-free". While some, like insoluble wheat bran, are indigestible, others like gums and pectins often added to processed foods are partially absorbed and do contribute some calories and impact blood sugar to a degree.
• Doesn't account for how other macronutrients impact carbohydrate absorption. Protein, fat, and the balance of a meal affect the glycemic response. Slower, more sustained energy comes from balanced meals rather than just low net carb foods.
• May lead to overconsumption of processed foods and total calories. Just because something is labeled "low net carbs" doesn't necessarily mean it's healthy or should be eaten in large amounts. Overall nutrition and portions still matter.
• Adds an additional stressful factor to track for weight management. Constantly worrying about staying under a net carb limit can be mentally taxing.

The Bottom Line

As with many nutrition trends, the usefulness of tracking net carbs is highly individual. Diabetics and those on medically-necessary ketogenic diets for conditions like epilepsy may benefit from considering net carbs under the guidance of their healthcare provider.

But for most people, a balanced approach focused on fiber-rich whole foods like vegetables, fruits, legumes and whole grains is more nutritious and sustainable than processed "low net carb" products. Aiming for 25-35 grams of fiber per day through whole foods helps with satiety and weight maintenance without the stress of tracking net carbs.

At the end of the day, to lose weight, a slight calorie deficit where you burn more than you consume is required, regardless of net carbs. Meeting fiber recommendations through nutritious foods and watching portions are the keys to sustainable weight management and overall health.