The age-old question of how many net carbs to eat for weight loss can be difficult to answer at times. The main issue here is that your body doesn’t really care about net vs. total carbs, or even grams of carbs. What really matters is the amount of carbohydrates that you eat above what you burn every day. That being said, there are a number of studies and research on this topic which will be discussed within this guide.
What are net carbs?
Calculating net carbs is a way to measure the carbohydrates your body actually digests. The “Total Carbohydrates” line on every Nutrition Facts label indicates the total amount of sugar, fiber, and other carbohydrates in a food. The thing is, your body doesn’t treat all of these carbs the same way.
Carbohydrate is a macronutrient that contains four calories per gram. Carbs are made up of long chains of sugar molecules.Dietary fiber is a form of carbohydrate; however, your body does not digest fiber, so it does not provide calories like other forms of carbohydrates.
When you take the total amount of carbs in food and subtract out the dietary fiber that does not contain calories, you get, drum roll please, net carbs, which is the remaining carbs that contain calories.
TOTAL CARBOHYDRATES – FIBER = NET CARBS
Essentially, the net carb theory is that certain carbs don’t need to be tallied as carbs for the day.
For example, there are 40 grams of carb in a cup of cooked quinoa and 5 grams of fiber.
40 grams total carbs – 5 grams fiber = 35 grams net carb. This cup of quinoa only has 35 grams of digestible, calorie-containing carbohydrate.
Why would you want to calculate net carbs?
Calculating net carbohydrates provides a more accurate number of calorie-containing nutrients in the foods we consume.
There are multiple reasons people may choose to calculate net carbs:
Diabetics use net carbs to dose their insulin.You can use net carbs to lose weight by identifying low-calorie foods.The keto diet requires a low-carb intake to drive the body into a state of ketosis.
How to use the power of net carbs to lose weight.
To lose weight, you have to create a calorie deficit by increasing calories burned and reducing calories ingested. When counting net carbs to lose weight, you can start by reducing the total calories you consume. Reducing total calories also naturally reduces your carb intake.
You can also use net carbs to identify which foods to eat more of. You can do this by choosing high-fiber foods; the more fiber in a carbohydrate food product, the lower the net carb will be.
Let’s use white rice, quinoa, and black beans as an example. They all contain about 40 grams of carb per one cup (cooked) with varying amounts of fiber.
White rice: 0.5 gram of fiber per cupQuinoa: 5 grams of fiber per cupBlack beans: 15 grams of fiber per cup
Because each of these foods has different fiber content and essentially the same total carb, it means they all have different amounts of net carb.
White rice: 44 g total carb – 0.5 g fiber = 43.5 g net carbQuinoa: 40 g total carb – 5 g fiber = 35 g net carbBlack beans: 40 g total carb – 15 g fiber = 25 g net carb
As you can see, the black beans have the lowest amount of net carbs per serving. White rice has the most.
The individual trying to reduce carbs to lose weight should choose the lower-net-carb beans more often than the other starches. In doing so, you will consume fewer digestible carbohydrates that contribute calories and impacts blood sugar.
Nearly all carb restriction diets, including keto and Atkins, focus more on restricting net carb rather than reducing total carb.
Let’s go over the difference between fiber and sugar alcohols.
Another ingredient you may have noticed on Nutrition Facts labels-especially manufactured foods like protein bars and sugar-free drinks, sugar-free candy, and sugar-free gum-is sugar alcohol.
Sugar alcohols are used in processed foods to add sweetness while providing fewer calories than table sugar. They can provide fewer calories than sugar because sugar alcohols are incompletely digested. Remember that fiber is not digested at all. These sweeteners are also quite different than dietary fiber, as many of them are not naturally occurring.
Types of sugar alcohols include:
Similar to fiber, you can subtract sugar alcohols from the total carbohydrate grams to calculate net carbs. However, the body doesn’t process all sugar alcohols the same. For most sugar alcohols, you can only subtract half of the total sugar alcohols in the net carb equation. Other sugar alcohols (like erythritol) are not digested, so you can subtract the full gram.
TOTAL CARBS – FIBER – (SUGAR ALCOHOL)/2 = NET CARBS
Fiber provides many benefits to the body outside of being a non-digestible carbohydrate. Fiber may help to lower cholesterol, improve digestive regularity, and helps increase satiety.
Sugar alcohols can serve as a form of prebiotic to feed good bacteria in your digestive tract, which is a plus, but they are also known to cause bloating, diarrhea, and gas, and long-term use is inconclusive in terms of health concerns.
What Are Total Carbs?
Total carbs are a more general measure of carb intake than net carbs. They take into account all the carbs in a food, including fiber and sugar alcohols.
For example, a salad may have 10 grams of total carbs, but if 8 grams of that are fiber, then it only has 2 grams of net carbs – the ones that actually matter for keto & weight loss.
However, fiber and sugar alcohols aren’t broken down by the body, so they don’t raise blood sugar.
That’s why some people choose to measure net carbs instead of total carbs.
What Are Net Carbs?
Net carbs are the net amount of total carbs in a food minus fiber and sugar alcohols. Since fiber & sugar alcohols don’t raise blood sugar like other carbs, most people choose to not track them on a low-carb diet.
Fiber is found in fruits, vegetables, whole grains, and many other vegetable foods. It doesn’t raise blood sugar, so it’s not counted as a carb.
Sugar alcohols are typically found in medicines, foods, and beverages. Unlike sugar, which is digested quickly, these carbs are not digested by the body and are not absorbed by the bloodstream.
Why Track Net Carbs for Weight Loss?
To lose weight on keto, it’s important to track net carbs instead of total carbs. This is because total carbs include harmless carbs like fiber & artificial sweeteners. However, net carbs only include the carbs that affect your blood sugar.
Food labels often list total carbs, but not fiber and sugar alcohols.
This can make it difficult to gauge your net carb intake and control your weight.
However, if you look at the ingredients, you can approximate how much fiber & artificial sweeteners are in a food & then subtract that from the total carbs.
How to Calculate Net Carbs
If you’re tracking net carbs, you need to subtract fiber and sugar alcohols from the total carbs listed on the food label. To calculate net carbs, do the following: Net carbs = Total carbs – fiber grams – sugar alcohol grams.
If you’re unsure of how many total carbs, fiber, or artificial sweeteners are in a food, you can always search on the internet to find out.
Limitations of Net Carbs for Keto Weight Loss
If you’re doing a keto diet to lose weight, it’s important to keep net carbs under 40 grams per day. That’s because if you eat a lot of net carbs, you’ll spike your insulin, & you’ll get kicked out of ketosis.
As long as you’re not eating any direct carb sources, like fruits, grains, desserts, etc, you’ll likely be under 40 grams of net carbs per day.
Focus on eating foods like eggs, meats, low-carb vegetables, nuts, & full-fat dairy.
Myths about carbs that are preventing you from losing weight
MYTH: Banning carbs means giving up bread and pasta
Fact: Yes . but it would also mean nixing fruits, vegetables and whole grains
Yes, that plate of steamed veggies you ate for lunch contained carbs.
“Carbohydrates vary widely in terms of their nutrient density, so everything from a green bean, which is a good source of fiber, protein [and other vitamins and minerals] to a slice of white bread, which does not offer much other than carbohydrates, is considered a carbohydrate,” says Pegah Jalali, MS, RD, CDN, an NYC-based pediatric dietitian.
Instead of saying, `I can’t eat that,’ ask, what is a source of carbs that will provide me with more nutrition?
She recommends that people move away from the obsession with banning all carbs and focus on the types of food they’re eating. “If you are eating mostly fruits and vegetables, then it is fine if your diet is high in carbohydrates,” says Jalali. “On the flip side, if your diet is high in carbohydrates, but you are eating mostly processed foods like packaged breads, cookies and chips then that is a completely different diet.”
Ferreira advises her clients to think about the different foods that contain carbohydrates on a spectrum. On one side are the foods you can eat in unlimited quantities – nutrient-dense, fiber-rich and whole-food carb sources like green veggies and fruit. Towards the middle are nutrient-dense, but also carbohydrate-dense, foods such as white potatoes, that should be balanced out with those at the eat as much as you can’ end, she says. On the other end of the spectrum are foods like breads and pasta. “While these still have a place in the diet, they require balancing out in order to create a diet that provides nutrients we need,” says Ferreira “I really urge people to start looking at carbs in this new way. Instead of saying,I can’t eat that,’ [ask] what is a source of carbs that will provide me with more nutrition?”
Myth: All carbs are created equal
Fact: There are simple and complex carbohydrates
“The main reason [carbs get a bad rap] is that when people think carbs’ they thinkstarch’, like white rice, pasta, potatoes or white bread,” says Bowerman. “While many refined carbs don’t offer up much nutritionally, there are lots of `good carbs’ – healthy foods that provide carbohydrates your body absolutely needs every day to function properly.”
In actuality there are three types of carbohydrates: fiber, sugar and starch. Where things get confusing is when we look at specific foods, which can contain different types of carbohydrates. They can either be labeled simple or complex based on their chemical makeup. Complex carbs “contain a complex chain of sugars as well as some fiber, protein and/or healthy fats, vitamins and minerals,” says Rebecca Lewis, registered dietitian at HelloFresh. “The presence of fiber, protein and fats is important because it slows digestion, prevents a spike in our blood-sugar levels, and helps us to feel full and satisfied for longer (i.e. curbs cravings).”
That’s why carbohydrate-containing foods like starchy vegetables, legumes and whole grains are included in many healthy diet plans.
Follow the 10:1 rule: Choose foods where for every 10 grams of carbs, there is 1 gram of fiber.
The simple carbs, often found in processed foods and drinks, are easier for the body to break down, meaning they don’t keep you full as long and can lead to erratic blood sugar levels.
That’s not to say that simple carbs are always bad for us.
“Simple carbohydrates are found in fruits, veggies and dairy – all of which are healthy choices as they also contain good stuff like vitamins, minerals, and fiber,” says Lewis. “However, simple carbs are also found in less healthy foods like refined grains, processed snacks, sweets, soda and juice, which lack extra nutrients. These foods are very quickly digested, which can cause swings in our blood sugar levels and often leave us hungry for more.”
The trick is to look for foods that have a more robust nutritional profile. That apple may have simple carbs, but it also contains a hefty dose of fiber to slow down the digestion of the sugars.
Image: Wholemeal Spelt Rigatoni with Green Asparagus, Cherry Tomato and Rocket Pesto on Plate
Supplementing pasta with fiber-rich veggies helps slow the breakdown of sugars in the body.
Myth: Carbs are fattening
Fact: It’s not the carbs making you fat, it’s the sugar and calories
“Anything is fattening if you eat too much of it, and not all carbohydrate-containing foods have the same calorie density,” says Bowerman. “This myth persists because many people who eat a lot of refined carbs and sugar do lose weight when they cut back on these foods. But it isn’t because they’ve cut out all of the carbs, it’s because they have cut out a lot of the calorie-dense foods.”
Research actually shows that while low-carb eaters tend to lose more weight at first, after one year, that weight loss levels out and is no different than those who eat a low-fat (moderate carb) diet.
That being said, when it comes to carbohydrate-containing foods and weight gain, sugar and excess calories tend to be the culprit.
“Really the secret behind carbohydrates is to identify and limit the amount of added sugar in your carbohydrate sources; highlight whole foods like fruits, vegetables, beans and whole grains; and pay attention to portion sizing carbohydrates along with your protein and fat sources,” says Amanda Markie, MS, RDN, LD, Outpatient Dietitian at UM Baltimore Washington Medical Center. “Sugar can be found naturally in foods like fruits and milk products, as well as being more concentrated into your processed foods like sodas, candy or baked goods,” explains Markie.
Research shows that while low-carb eaters tend to lose more weight at first, after one year, that weight loss levels out and is no different than those who eat a moderate carb diet.
So you want to ensure that you’re choosing sources of carbohydrates that have this naturally-occurring sugar.
“Also look for higher dietary fiber with a lower amount of added sugar, which you can identify if it is one of the first ingredients on the ingredients list,” says Markie. “Limit those foods that have sugar within the first two to three ingredients.”
And just because you’re choosing the higher-fiber, low-sugar options doesn’t mean you can eat them in unlimited qualities: portions matter.
“Four cups of quinoa will make anyone gain weight. The quantity is the key strategy,” said Monica Auslander, MS, RDN, the founder of Essence Nutrition. “For example, I’ll eat steel cut oatmeal, but only 1/3 cup a day. I’ll eat beans, but only 1/2 cup at a time. I’m a petite person and not an athlete, so I can’t afford to have three slices of Ezekiel bread for breakfast, a sweet potato at lunch, and three cups of quinoa at dinner.”
Myth: Carbohydrates spike your blood sugar
Fact: The right carbs stabilize blood-sugar levels for sustained energy
A 2014 study published in the Nutrition Journal found that participants who ate a high-carbohydrate, high-fiber, vegan diet (they got 80 percent of their calories from carbs) actually saw a drop in average blood sugar, plus lost weight and had significant improvements in blood pressure.
Plus, that glucose that our bodies gleans from digestible carb is needed for the functioning of multiple organs, including the brain. So that sugar in the blood stream isn’t just okay – it’s necessary. The problem is when they are released all at once in high doses.
“One thing that we must all remember is that carbohydrates are essential to fuel your brain, boost our energy and maintain our metabolism. The key is to eat the right kinds of food that contain carbohydrates,” says Meghan Daw, RD, LDN, from Fresh Thyme Farmers Market. “These foods contain carbohydrates that are more complex, meaning they contain fiber and other nutrients that take time to digest and allow a slow release of sugar into the body. This slow release does increase blood sugar levels over time but not all at once, preventing some unwanted blood sugar level spikes and symptoms that come along with those spikes.”