What Are Net Carbs and Should You Count Them?Aug 6, 2019
If you care more about your net carbs than your net worth, you might want to take a step back and reevaluate. This concept started as a gimmick for food manufacturers to market their products as being “low-carb.” Now it’s something that many ketogenic diet proponents advise you calculate. But most nutrition experts say you don’t need to worry about how many net carbs you eat in a day. So what’s the deal? Here’s everything you need to know about net carbs.
What Are Net Carbs?
The difference between carbs and net carbs is that “carbs” entail all carbohydrates in a food, whereas “net carbs” are only the carbohydrates that are thought to impact blood sugar.
How Do You Calculate Net Carbs?
If you’re wondering how to calculate net carbs, there’s no need for a fancy net carb calculator. You just need to do some simple math! To figure out the net carbs in an item of food, you simply take the total number of carbs and subtract the grams of fiber and sugar alcohols (which come from plant products). The final number is the net carbs.
What Exactly Are Carbs, Again?
Let’s back up a bit and explain what exactly carbohydrates are. Carbs are a macronutrient and your body’s main source of fuel. When you eat carbs, your body breaks them down into simple sugars and then stores them to use for energy.
But there are two types of carbs — simple and complex carbs — which act differently in your body. Fruit, vegetables, and whole grains are complex carbs that provide fiber, vitamins, minerals, and phytonutrients. Then there are simple carbs, like gummy bears or hard candy, are just pure sugar.
“Carbs often get a bad rap, but what people are missing is that there are carbs that provide valuable nutrients, and then there are carbs that are just empty calories,” explains Krista Maguire, RD, CSSD, nutrition manager at Openfit.
Net carbs and blood sugar
With that cleared up, let’s get back to net carbs. Although there is no widely regulated definition of “net carbs” (sometimes called “impact carbs”), they are often understood as the amount of carbs left in a food when you subtract the grams of fiber and sugar alcohols. You subtract these two things because your body doesn’t actually absorb them, and therefore are not believed to impact blood sugar.
“For example, processed refined carbs [like the gummy bears] tend to cause a blood sugar spike, while fiber-rich foods [like the fruits and veggies] are slowly absorbed and the dietary fiber is non-digestible,” Maguire says.
Even though you don’t completely digest fiber, it’s still an important part of your diet. A high-fiber diet can help you feel fuller and longer, which may ultimately help you lose weight.
There are two types of fiber: soluble and insoluble. Soluble fiber is partially digested. It dissolves in water and forms a gel that slows the movement of food traveling through your digestive system, explains Keri Gans, RDN based in New York. Insoluble fiber leaves the body completely undigested. It creates bulk in our stool, helping to prevent constipation.
“Your body handles the digestion of fiber differently than the way it handles refined carbohydrates,” Maguire says. “A portion of the fiber simply passes through your digestive system intact, so it’s less likely to cause a spike in blood sugar.” That’s why you don’t count fiber when you calculate net carbs.
Should I Count Net Carbs?
Both Gans and Maguire say there’s no need to worry about counting net carbs, even if you live with diabetes or are trying the keto diet. The American Diabetes Association advises that diabetics look at the total carbohydrates in foods and monitor their blood glucose to see how different foods affect it. And those on the ketogenic diet can only know if they are in ketosis by testing for ketone bodies. “No one officially knows the impact fiber has on ketosis,” Maguire says.
If you are concerned about your carbohydrate intake, talk to a registered dietitian (RD or RDN). Otherwise, forget about net carbs. “Balancing blood sugar doesn’t come from a math equation,” Maguire says. “It’s simple to do by consuming a balanced diet filled with naturally healthful foods that also provide a myriad of benefits in addition to blood sugar balance.”