How do you calculate carbs per 100g
How to Calculate Net Carbs
Net carbs refers to carbs that are absorbed by your body. To calculate the net carbs in whole foods, you subtract the fiber from the total number of carbs. To calculate the net carbs in processed foods, you subtract the fiber and a portion of the sugar alcohols.
Whether to count net or total carbs is a controversial topic within the low-carb community.
For starters, the term net carbs isnt officially recognized or agreed upon by nutrition experts. In addition, due to conflicting and outdated information, figuring out how to calculate net carbs can be confusing.
In fact, the net carb claims on packaged foods may not reflect the number of carbs your body actually absorbs.
Luckily, knowing how your body processes different types of carbs may help you achieve your target blood sugar, weight loss and health goals.
This article looks at the science behind net carbs, provides simple calculations for determining your intake and discusses the pros and cons of counting net carbs.
What Are Net (Digestible) Carbs?
Net carbs are sometimes referred to as digestible or impact carbs. The terms refer to carbs that are absorbed by the body, including both simple and complex carbs.
Simple carbs contain one or two sugar units linked together and are found in foods like fruits, vegetables, milk, sugar, honey and syrup.
Complex carbs contain many sugar units linked together and are found in grains and starchy vegetables like potatoes.
When you eat a carb-containing food, most of the carbs are broken down into individual sugar units by enzymes produced in your small intestine. Your body can only absorb individual sugar units.
However, some carbs cant be broken down into individual sugars, whereas others are only partially broken down and absorbed. These include fiber and sugar alcohols.
Because of this, most fiber and sugar alcohols can be subtracted from total carbs when calculating net carbs.
Summary:Net (digestible) carbs are broken down into individual sugar units and absorbed into your bloodstream. However, your body processes fiber and sugar alcohol carbs differently than digestible carbs.
How Your Body Handles Fiber Carbs
Fiber is a unique form of carbs in terms of its digestion and effects on your body.
Unlike starch and sugar, naturally occurring fiber isnt absorbed in your small intestine.
This is because the links between sugar units cant be broken down by the enzymes in your digestive tract. Therefore, fiber passes directly into the colon (
However, its fate after that depends on what type of fiber it is.
There are two broad categories of fiber: insoluble and soluble. About two-thirds of the fiber you eat is insoluble, while the other third is soluble.
Insoluble fiber does not dissolve in water. It creates a bulkier stool and can help prevent constipation. This type of fiber leaves the colon unchanged, provides no calories and has no effect on blood sugar or insulin levels (
By contrast, soluble fiber dissolves in water and forms a gel that slows down foods movement through your system and can help make you feel full (
After arriving in your colon, soluble fibers are fermented into short-chain fatty acids (SCFAs) by bacteria. These SCFAs help keep your gut healthy and may also provide a number of other health benefits.
Studies have shown that the fermentation of 1 gram of soluble fiber to SCFAs provides about 12 calories, depending on the type of fiber (
Since about one-third of the fiber in most foods is soluble, a serving of food containing 6 grams of fiber would contribute up to 4 calories in the form of SCFAs.
However, while soluble fiber does provide a few calories, it doesnt seem to increase blood glucose. In fact, the most recent research suggests that its effects in the gut help reduce blood sugar levels (
Many studies have shown that soluble fiber may lead to better blood sugar control, increased insulin sensitivity and the absorption of fewer calories (
On the other hand, one processed fiber called isomaltooligosaccharide (IMO) seems to be partially absorbed in the small intestine like non-fiber carbs, which may raise blood sugar (
Recently, several food manufacturers replaced IMO with other forms of fiber in their products. However, IMO can still be found in a number of low-carb foods.
Summary:Naturally occurring fiber is not absorbed in the small intestine. Gut bacteria ferment soluble fiber into SCFAs, which contribute minimal calories and have neutral or beneficial effects on blood sugar.
How Your Body Handles Sugar Alcohol Carbs
Sugar alcohols are processed similarly to fiber, with a few important differences.
Many sugar alcohols are only partially absorbed in the small intestine, and there is a lot of variation among different types.
Researchers report the small intestine absorbs 290% of sugar alcohols. However, some are only briefly absorbed into the bloodstream and then excreted in urine (
In addition, these sugar alcohols can have varying effects on blood sugar and insulin levels, although all are considerably lower than sugar.
Here is a list of the glycemic and insulin indexes for the most common sugar alcohols. By comparison, glucoses glycemic and insulin index are both 100 (
- Erythritol: Glycemic index 0, insulin index 2
- Isomalt: Glycemic index 9, insulin index 6
- Maltitol: Glycemic index 35, insulin index 27
- Sorbitol: Glycemic index 9, insulin index 11
- Xylitol: Glycemic index 13, insulin index 11
Maltitol is the most commonly used sugar alcohol in processed foods, including low-carb protein bars and sugar-free candy.
Its partially absorbed in the small intestine, and the remainder is fermented by bacteria in the colon. Its also been found to contribute about 33.5 calories per gram, compared with 4 calories per gram for sugar (
Anecdotally, maltitol has been reported to increase blood sugar levels in people with diabetes and prediabetes.
In terms of net carbs, erythritol seems to be the best choice all around.
About 90% of it is absorbed in the small intestine and then excreted in the urine. The remaining 10% is fermented to SCFAs in the colon, making it essentially carb-free, calorie-free and unlikely to cause digestive troubles (
Studies have shown that other sugar alcohols are also partially absorbed and may raise blood sugar, although to a lesser extent than maltitol. However, they seem to cause significant bloating, gas and loose stools in many people (
Importantly, the controlled studies on sugar alcohols involved fewer than 10 people, and blood sugar levels werent always tested.
Overall, sugar alcohols dont seem to have a major effect on blood sugar and insulin levels, but individual responses may vary, especially among those with diabetes or prediabetes.
Summary:The absorption and fermentation of sugar alcohols vary widely. With the exception of erythritol, most are capable of raising blood sugar and insulin at least slightly.
Calculating Net Carbs in Whole Foods
Whole foods contain naturally occurring fiber. Therefore, you can simply subtract the fiber from the total carbs to get the net carbs.
The
For example, a medium avocado contains 17.1 grams of total carbs, 13.5 grams of which is fiber (25).
So 17.1 grams of total carbs 13.5 grams of fiber = 3.6 grams of net carbs.
Summary:Whole foods contain fiber, which can be subtracted when calculating net carbs. Formula: total carbs fiber = net carbs.
Calculating Net Carbs in Processed Foods
To calculate the net carbs in a packaged product, the more information you have, the better.
Calculating Net Carbs From Fiber
Most fiber can be completely subtracted from the total carbs listed on the nutrition label.
If you live outside the US, the total carbohydrate line already has the fiber removed and listed separately.
However, if the fiber isomaltooligosaccharide (IMO) is in the ingredients list, subtract only half of the fiber carbs.
Calculating Net Carbs From Sugar Alcohols
Generally speaking, half of the carbs from sugar alcohols can be subtracted from the total carbs listed on the nutrition label.
Erythritol is an exception. If its the only sugar alcohol in the ingredients list, its carbs can be completely subtracted from the total carbs.
This value may be different than the number of net carbs stated on the product label, since many companies subtract all fiber and sugar alcohol carbs when calculating net carbs.
For example, a maltitol-sweetened Atkins bar label states that it contains 3 grams of net carbs.
However, when subtracting only half the carbs from sugar alcohols, the net carb value is 8.5 grams: 23 grams of total carbs 9 grams of fiber 11 grams sugar alcohols (11 grams X 0.5 = 5.5 grams) = 8.5 grams of net carbs.
Summary:A portion of fiber and sugar alcohols can be subtracted from total carbs to calculate net carbs. Formula: total carbs minus fiber (or half of IMO) minus half the carbs from sugar alcohols (other than erythritol) = net carbs.
Pros and Cons of Counting Net Carbs
There are pros and cons to counting net carbs, rather than total carbs.
Advantages
- Less restrictive: Counting net carbs may increase food choices. For instance, although blackberries, avocados and seeds are mainly fiber, they may be minimized on a ketogenic diet restricted to 20 grams of total carbs daily.
- May promote higher fiber intake: Fiber-rich foods have been shown to promote fullness, decrease blood sugar and reduce calorie absorption. Limiting them may backfire in some cases (
8 ,9 ,10 ,11 ). - Reduced risk of hypoglycemia in people who use insulin: Taking insulin to cover all carbs without adjusting for high-fiber and erythritol-containing foods may potentially result in hypoglycemia, or low blood sugar.
Disadvantages
- Not 100% accurate: At this time, its not possible to calculate net carbs with complete precision due to the varying effects of processing on fiber, the combination of sugar alcohols used in products and individual response.
- May not work as well for some with type 1 diabetes: While subtracting fiber carbs may help prevent low blood sugar in some people with type 1 diabetes, others report counting all carbs makes it easier to manage blood sugar.
- May lead to high intake of sugar-free treats: Overindulging in bars marketed as low in net carbs may stall weight loss, increase blood sugar and trigger other health problems.
Ultimately, the decision about whether to count total or net carbs should be based on what works best for you.
Summary:Counting net or digestible carbs may be helpful for some people, while others may prefer to count total carbs. The choice is a personal one.
The debate about whether its more accurate to count total or net carbs isnt likely to go away anytime soon.
However, understanding how your body processes different kinds of carbs can help you manage your blood sugar, weight and overall health.
Calculating net carbs is one way to do this. The term net carbs simply refers to carbs that are absorbed by the body.
To calculate the net carbs in whole foods, subtract the fiber from the total number of carbs. To calculate the net carbs in processed foods, subtract the fiber and a portion of the sugar alcohols.
Nevertheless, remember that the net carbs listed on food labels can be misleading, and individual responses may also vary.
If you find that counting net carbs leads to higher-than-expected blood sugar levels or other issues, you may prefer to count total carbs instead.
The key is to eat the number of carbs that allows you to achieve your health goals, no matter how you count them.
Carbohydrate Calculator: How Many Grams of Carbs Should You Eat?
Carbohydrates are the energy source your body relies on most throughout the day. They fuel your workouts and provide energy for movement and brain function. The calculator on this page provides recommendations for a moderate-carbohydrate diet, with slightly lower carb levels for fat loss and higher levels for muscle gains.
If you're new to tracking your macros, use the calculator's recommendations to get a good starting baseline. If you're transitioning from a so-called "standard American diet" with soda and crunchy snacks, this might already be lower than you're used to! Then, if you decide you want to try a lower-carb or ketogenic approach, you can experiment with reducing your carb levels.
This daily carbohydrate target can help you lose weight in the form of body fat while minimizing muscle loss. Here are the next steps on your weight -loss journey:
1. Pick a weight-loss workout plan.
A well-designed program is an essential part of turning hard numbers into hard-body results! Here are the most popular ones from BodyFit:
2. Calculate your macros.
Carbohydrates are just one of the three macronutrients. To get targets for the other two, as well as a daily calorie target, use the Bodybuilding.com Macronutrient Calculator.
3. Learn about the best fat-loss supplements.
Supplements can help you accelerate your results once you have your carbohydrate intake and training in place. Krissy Kendall, Ph.D., shares her recommendations in the article, "5 Ways to Up Your Fat-Loss Supplement Game."
4. Join a fitness community.
For over 10 years, members of BodySpace have been helping each other build their best bodies. Join the world's strongest fitness community!
This daily carbohydrate target can help you focus on body recomposition, or gradually burning fat and building muscle, while focusing on your health. Here are the next steps on your journey to customize your nutrition:
1. Pick a workout plan.
A well-designed program is an essential part of staying motivated and seeing results. Here are some of our most popular programs from BodyFit:
2. Calculate your macros.
Carbohydrates are just one of the three macronutrients. To get targets for the other two, as well as a daily calorie target, use the Bodybuilding.com Macronutrient Calculator.
3. Learn about the best health-focused supplements.
Supplements can help you accelerate your results and support your training once you have your carbohydrate target and training in place. Chris Lockwood, Ph.D., shares what to take and why in the article, "Start Here: The Most Important Supplements for Every Body."
4. Join a fitness community.
For over 10 years, members of BodySpace have been helping each other build their best bodies. Join the world's strongest fitness community!
This daily carbohydrate target can help you build lean muscle mass while minimizing body-fat gains. Here are the next steps on your journey to see the scale go up:
1. Pick a muscle-building workout plan.
A well-designed program is an essential part of turning hard numbers like calories into hard-body results! Here are the most popular ones from BodyFit:
2. Calculate your macros.
Carbohydrates are just one of the three macronutrients. To get targets for the other two, as well as a daily calorie target, use the Bodybuilding.com Macronutrient Calculator.
3. Learn about the best supplements for gaining muscle.
Supplements can help you accelerate your muscle-building results once you have your carbohydrate intake and training dialed in. Krissy Kendall, Ph.D., shares her recommendations in the article, "8 Proven Supplements for Muscle Growth and Strength."
4. Join a fitness community.
For over 10 years, members of BodySpace have been helping each other build their best bodies. Join the world's strongest fitness community!
MAINTAIN CURRENT WEIGHT
First time tracking macros? Or not sure which goal is right for you? Then start with "maintenance." In theory, this is an amount of carbs in line with the number of calories that you burn to maintain your current weight. Many nutritionists say before you start cutting or adding calories or tweaking your macros, you should spend some time at maintenance level and get more comfortable with tracking your foods and portion sizes.
LOSE WEIGHT
If you know that you're ready to lose a few pounds and you have some experience counting calories or tracking macros, select "lose weight." This will give you a carbohydrate target in line with 200-700 calories below maintenance, depending on your activity level, and a 40/40/20 macronutrient breakdown of carbs, protein, and fats. This is a popular "sweet spot," both calorically and in terms of macronutrients, for healthy, sustainable weight loss.
GAIN WEIGHT
Gaining weightespecially as musclesounds easy enough. Train hard, eat big, right? But once the fork hits the plate, plenty of people find they need to eat far more than they realized to see the scale move up. Selecting "gain weight" will give you an amount of carbs in line with 500 calories above maintenance, on a 40/30/30 macro split. If this doesn't make the scale go up after a couple of weeks, you may need to add a few hundred more calories.
ACTIVITY LEVEL
This choice should reflect the amount of activity in your life based on how you exercise and how physically active your life and/or job is. Nutritional researchers agree that calorie estimates should take more into account than just the amount you exercise. Here's how to figure out what's right for you:
- Sedentary: You work at a desk job and you don't do much housework, walking, or exercising.
- Lightly active: You don't exercise much, but you go for walks 1-3 times per week and are on your feet doing housework during some of the day.
- Moderately active: You exercise 3-5 times a week and stay moving throughout the day with non-exercise activities.
- Very active: You exercise intensely or play vigorous sports on most days.
- Extra active: You exercise intensely or play vigorous sports nearly every day, including occasional "two a days." You also work a physical job or are on your feet most of the time.
How Do I Determine the Carbs in My Food?
You can do this using food labels, as well as by weighing out your food on a food scale and using one of the many online nutritional databases.
Weighing food may seem like a lot of counting and not much fun, but it gets easier over time. Fitness coach Vince Del Monte says in the article, "From Here to Macros: 4 Steps to Better Nutrition" that you quickly learn to "eyeball" quantities of both calories and macronutrients after just a few weeks of practice.
Bodybuilding.com has also created visual guides to help you learn these skills:
Are Carbs Bad for Me?
No! Carbohydrates get a bad rap because when eaten in excess, they may add adipose tissue, aka fat. You'll notice that the calculator recommends lower carb levels for fat loss and higher for muscle gains. But if incorporated into a diet in the right levels and at the right times, carbs can provide all of the benefits with none of the cost.
According to registered dietician Paul Salter, the best times to eat carbs are before, during, and after workouts, so they can supply you with energy and replenish the glycogen you expend during long training sessions.
Another great time to carb up? Dinnertime. Many people think you shouldn't eat carbs at night if you want to stay lean, but this is a myth. Not only will carbs after dark not hurt you, but eating most of your carbohydrates in the evening can actually help you lose fat and optimize your hormones.
What Are the Best Types of Carbs for Losing Weight and Building Muscle?
For the most part, it's best to opt for complex carbs from whole foods to fuel your day. These foods break down more slowly and provide sustained energy instead of spikes and crashes. Great sources of complex carbs include sweet potatoes, brown rice, fruit, and starchy veggies like peas and carrots, which all have plenty of fiber to slow down their digestion. These foods also have more of their micronutrients intact compared to processed foods.
But there's a time and a place for simple carbs, too. Even so-called "bad carbs" like certain types of candy, aren't always bad. When you eat them during training or right after exercise, they can help restore your muscle glycogen more quickly and start your recovery sooner. In other words, the sugar goes straight to your muscles to help you heal up from your last workout and prime you for your next one.
Protein and carbs are the perfect post-workout combo to support hard training and help you nail your goals. - View All
GET SYSTEMATIC ABOUT YOUR RESULTS
Once you have your daily carb intake, it's time to take the same kind of strategic approach to the rest of your training and nutrition. These popular calculators can help you dial in your plan!
