Track your carbs and eat them, too? That's the lofty promise behind counting net carbs over total carbs.
If you're on a low-carb diet such as keto or you limit carbs to manage a medical condition, you're likely quite familiar with counting carbs. But in recent years, dietitians and other experts have made a case for tallying up net carbs — also sometimes called "digestible carbs," "active carbs" or "impact carbs" — instead of the total carbs you take in.
So, What Are Net Carbs?
When you're counting carbs, it's easy to think of them as an enemy to avoid completely. But carbs serve an important purpose: They're converted into energy that's either used or stored in the body. Along with fat and protein, they're one of the three essential macronutrients required to keep your body running smoothly.
There are three main forms of carbohydrates: fiber, sugar and starch, according to the Mayo Clinic. While sugar and starch are both digested and turn into blood glucose (aka blood sugar), most of the fiber you eat won't be digested at all, according to the American Diabetes Association.
That's where net carbs come in.
Instead of counting total carbs, tracking net carbs allows you to tally up only the ones your body actually digests. While there's no standard medical or scientific definition for net carbs, they're generally calculated by taking total carbs and subtracting fiber and sugar alcohols (a commercially produced form of carbs that act as a sweetener, per the FDA). The new total after subtracting these is your net carb total.
Here's How the Equation Looks
Total carbs – fiber – sugar alcohols = net carbs
Essentially, the sugar and starches are your net carbs. To understand why net carbs do not take fiber or sugar alcohols into account, it's important to know how each of these types of carbohydrates affect the body and why they're so important.
The Benefits of Tracking Net Carbs Instead of Total Carbs
This method of carb-tracking recognizes that not all carbs are the same. That's because some are indigestible and won't affect your blood sugar. So if you're restricting the number of carbs you eat, counting net carbs allows you to choose more thoughtfully. Simply put: You'll be able to eat a variety of satiating foods (hello, whole grains) while still hitting your target carb or blood sugar levels.
Consider these perks that might convince you to board the net-carb bandwagon.
- You'll likely eat more nutrient-dense foods: "Tracking net carbs can help someone enjoy a larger and more filling amount of carbs at a meal," Dylan Murphy, RD, LDN and owner of Dylan Murphy Nutrition. She compares a medium-sized pear to a granola bar — both may have a similar number of total carbs, but the pear has fewer net carbs and more fiber. This, Murphy says, can keep you full longer and prevent a spike in blood sugar.
- You'll focus on getting more fiber: "The advantage of tracking net carbs instead of total carbs is you don't factor fiber into your carb count for the meal. Fiber is processed differently in our bodies than carbs are," says Murphy. Therefore, people may opt for higher fiber foods and focus on slashing sugar from their diet.
- You'll eat less sugar: Focusing on high-fiber foods that are low in net carbs means you'll nix the amount of sugar and starches you eat on the daily.
Want to Track Net Carbs Without Doing the Math?
Let's zero in on that second benefit a bit. You'll find dietary fiber, a type of carbohydrate, listed on food labels under "total carbohydrates," but fiber is digested differently than white grains or sugar-filled candy, which turn into glucose fairly rapidly in the body. Unlike these simple carbs, fiber helps fill us up, then passes through our body, aiding in digestion and regularity.
We hear about the importance of fiber often when it comes to health and nutrition because eating fiber helps lower cholesterol levels, prevent constipation and control blood sugar levels, according to the Mayo Clinic.
It can also help you maintain a healthy weight since fiber-rich foods take longer to eat and are more filling, the Mayo Clinic notes. "Fiber slows down our digestion and keeps us full for longer," says Murphy.
A January 2018 study update in the Journal of Nutrition found a high-fiber diet is tied to lowering the risk of developing type 2 diabetes. High fiber intake during the teen years and into early adulthood is also tied to reducing breast cancer risk, according to a large February 2016 study published in Pediatrics. And, several studies have shown that dietary fiber may be linked to a reduced risk of heart disease, according to the Harvard T.H. Chan School of Public Health.
A Note on Sugar Alcohols
Sugar alcohols provide sweetness with fewer calories than regular sugar and have less of an effect on blood sugar than other carbs, per the FDA, which is why we subtract them when counting net carbs.
But because they aren’t digested or absorbed in the same way as sugar, sugar alcohols can often cause GI issues (such as gassiness and a laxative effect). It's a good idea to slowly introduce foods with sugar alcohols until you're aware of your tolerance to them. The sugar alcohol erythritol is the least likely to cause GI upset.
How to Get More Fiber on a Low-Carb Diet
For many people, ditching carby foods is an effective solution to lose or maintain weight. Often, however, those who restrict their carb intake find that they don't feel full as a result.
Here's the key to feeling full and losing weight: Getting more fiber while nixing sugar, which is where tracking net carbs helps.
The FDA notes that people in the United States don't get enough fiber and fall below the 25-gram-per-day recommendation. Here are some easy ways to increase fiber intake:
And when you're adding more fiber to your diet, make sure to drink plenty of water along with it to prevent consipation.
Read more: 19 High-Fiber Foods — Some May Surprise You!
"As with tracking food in general, tracking carbs or net carbs can quickly turn into disordered eating if not managed mindfully," Murphy points out. It's important to keep in mind that even if the net carbs in a certain food are low, that doesn't mean the calories are low. If your goal is weight loss or weight management, it's important to always read the full nutritional label, too.
Should You Track Net Carbs if You Have Diabetes?
As mentioned earlier, the term "net carbs" still doesn't have a medically or scientifically standardized definition. So, if you have diabetes, consider subtracting dietary fiber from carbohydrates in food with more than 5 grams of fiber, the Diabetes Research Institute at the University of Miami suggests.
The Institute also recommends only subtracting half — and not all — of the sugar alcohols from the total carbohydrates. Remember, sugar alcohols can have some effect on blood sugar (it's just less of than effect than other types of carbs).
It's important for people living with diabetes to closely monitor their blood sugar levels and work with their health care provider to determine an appropriate net carb amount per day and which foods make the most sense for them to eat in conjunction with any medication or insulin regimen.
- Food and Drug Administration: "Sugar Alcohols Facts Sheet"
- FDA Consumer Updates: "Paws Off Xylitol; It's Dangerous for Dogs"
- Linus Pauling Institute: "Fiber"
- Nutrition Reviews Journal: "Health Benefits of Dietary Fiber"
- Diabetes Research Institute: "Carbohydrate Counting"
- American Journal of Lifestyle Medicine: "Closing America's Fiber Gap"
- Journal of Nutrition: "Impact of Dietary Fiber Consumption on Insulin Resistance and the Prevention of Type 2 Diabetes."
- Mayo Clinic: "Carbohydrates: How Carbs Fit Into a Healthy Diet"
- American Diabetes Association: "Types of Carbohydrates"
- Mayo Clinic: "Dietary fiber: Essential for a Healthy Diet"
- Pediatrics: "Dietary Fiber Intake in Young Adults and Breast Cancer Risk"
- Harvard T.H. Chan School of Public Health: "Fiber"
- FDA: "Dietary Fiber"