Net Carbs vs Total Carbs: Which Is Better For Blood Sugar Control?

Kathleen says: “I am unclear about net carbs vs total carbs. I eat a lot of veggies, which increases my total carbs to over 100 grams per day, but my net carbs are usually between 40-60. Should I focus more on the total or the net carbs eaten? I have been diagnosed with prediabetes, for several years now. Thank you!”

This is a fantastic question!

If you look around the low carb websites online, the Atkins diet, ketogenic diet, or low carb products like Atkins, you’ll see that oftentimes they use”net carbs.”

But what about for diabetes, is net carbs better than calculating your total carb intake?

That’s exactly what we’re here to workshop together now so you can get a better understanding about how total carbs and net carbs effect you and your blood sugar levels.

Net Carbs vs Total Carbs: What’s the Difference?

To explain it simply, total carbohydrates is obviously the total amount of carbs contained in any food item.

Whereas the net carbs removes certain elements from the total carb count to provide you with the “net effect” of those carb-containing foods on the body.

How to Determine Net Carbs

You can use this simple formula to calculate the number of net carbs in any given food:

Total carbs minus fiber = net carbs

Let’s break this formula down using an example.

First, check out the nutrition facts label from a can of green beans. A serving of these beans contains 7 grams of total carbohydrates.

Now look a little closer at the label and you will notice that a serving of green beans also contains 3.4 grams of dietary fiber.

So if we plug these numbers into the formula, it looks like this…

7 g (total carbs) – 3.4 g (fiber) = 3.6 g (net carbs)

When you subtract the fiber content it “cancels out” some of the total carbs, and you’re left with the “net effect” of the food.

But… there is a bit more to it than that. So let’s look at fiber for a sec…

What’s the Deal with Fiber?

In short, fiber is the “indigestible” part of plant foods. Fiber isn’t digested and absorbed by the body so it contains no calories and it doesn’t raise your blood sugar.

When it comes to fiber, there are many different types to be found in various food sources:

Inulin. Found in artichokes, garlic, leeks, onions, asparagus, chicory root, wheat and rye.

Resistant starch. Found in cooked and cooled rice and potatoes, beans and legumes, grains, seeds and green bananas.

Pectin. Mainly found in apples, oranges, citrus peels, carrots, cherries and apricots, along with smaller amounts in other fruits and berries.

Oligofructose. Like inulin, this fiber is also found in artichokes, garlic, leeks, onions, chicory and asparagus.

Fructooligosaccharides. Found in a wide range of fruits and vegetables but particularly bananas, onions, garlic and asparagus.

Cellulose. Forms the structure of most vegetables so eating an abundant variety is important.

You won’t hear of these types of fiber much. Instead, you will often hear the terms “soluble fiber” and “insoluble fiber.”

Soluble fiber: turns into viscous gel-like substances that slow the rate of digestion, including the absorption of sugar/ glucose.

Insoluble fiber: forms the structure of most plants and it’s mostly resistant to digestion. This means it forms a lattice work in our gut and moves along our digestive tract, adding weight to waste material and assisting with digestion, and pooping.

Advantages of a high fiber diet:

• Better blood glucose and A1c control
• Increased weight loss
• Decreased inflammation
• Lower insulin response and improved insulin sensitivity
• Promote healthy gut bacteria

Downfalls of Low Carb “Products”

You’ll often see lots of low carb food products packed with “man-made” fiber and “sugar alcohols.” And many of these products go ahead and claim a 25 gram food product has only 1 gram net carbs.

There are two dangers here:

1. Man-made fibers: while “man-made” fibers are still technically fibers, they certainly aren’t the same as natural plant fibers. A processed fiber is still a processed “man-made” fiber so while they will bring a “processed” foods net carbs down, you’re still not consuming the types of foods you should be – namely: natural whole food sources.
2. Sugar alcohols: most food manufacturers subtract the entire amount of sugar alcohols from the total carb count, which is actually inaccurate. This means you could consume a low carb food product that may in fact impact your blood sugar levels much more than you expect.

So let’s take a look at sugar alcohols more closely…

Beware of Sugar Alcohols

Sugar alcohols are both confusing and annoying. For one thing, they aren’t sugar. For another, they aren’t alcohol.

They are compounds similar in structure to sugar and taste sweet to varying levels, but are not completely absorbed and therefore, do not have the same degree of impact on blood sugar.

But that’s the catch: some sugar alcohols have no impact on blood glucose whereas others have almost the same impact as sugar itself. And unfortunately, when you look at the nutrition facts label, all of these sugar alcohols are lumped into the same category and manufacturers get away with subtracting all of them from the carb count, even when it’s not accurate and could in fact be harmful to people!

For example, erythritol has zero calories and a glycemic index of zero. Whereas xylitol has 2.4 calories per gram and a glycemic index of 12, which will certainly still impact blood glucose to some degree.

Here’s the sugar alcohol shortlist (C=calories, GI=glycemic index, IE=insulin index):

• Erythritol – C: 0-0.2, GI: 0, IE: 2
• Xylitol – C: 2.4, GI: 13, IE: 11
• Sorbitol – C: 2.6, GI: 9, IE: 11
• Mannitol – C: 1.6, GI: 0, IE: 0
• Isomalt – C: 2.0, GI: 9, IE: 6
• Lactitol – C: 2.0, GI: 6, IE: 4
• Maltitol – C: 2.1, GI: 35, IE: 27
• Polyglycitol – C: 3, GI: 39, IE: 23

All sugar alcohols are low glycemic index, as anything under 55 is considered low – though of course, the lower the better. The insulin index refers to how the sugar alcohols impact insulin levels. Much like the glycemic index, the higher the number, the more of an impact the sugar alcohol has.

So in terms of carb counting, what are you to do about sugar alcohols then?

What About Calculating Sugar?

Some people do get confused about the whole sugar and carb counting ordeal. But when it comes to gaining good control, counting sugar is not really important.

Why?

Because sugar is a subcategory of the total carbohydrate count. What that means is that the sugar is already factored in when you check the total carbs.

And one thing about nutrition labels is they do not separate “added” sugar from the natural sugar found in whole foods like vegetables. For instance, 1 cup chopped broccoli contains 1.5 grams of sugar but it’s clearly not “added” sugar, nor is it bad for your health.

Of course, you want to stay away from “added” sugars. And the only way to determine this is to assess the ingredients list of a food product, as you can’t really tell from the nutrition label.

Since sugar is a subcategory of the total carbs, it’s important to remember that ALL carbs (with fiber being an exception) will break down during digestion and convert to glucose/sugar, and therefore raise your blood sugar levels to some degree.

Total Carb vs. Net Carbs Examples

Now that you’re familiar with fiber, you can use the formula to calculate the net carb values of whole foods. To find nutrition data for foods, you can search the USDA Food Database or FatSecret.

Once you know the nutrition details of a food, just plug in the simple formula to calculate the net carbs (Formula: total carbs minus fiber = net carbs).

Here are a few examples (the bold number is the amount of net carbs):

• Broccoli (1/2 cup): 5.6g – 2.6g = 3g
• Avocado (1 whole): 17g – 6.5g = 10.5g
• Chia seeds (1 oz ): 12g – 10g = 2g
• Whole Wheat Pasta (1/2 cup): 18.6g – 3.26g = 15.4g
• White Rice Pasta (1/2 cup): 22g – 0.9g = 21.1g
• Oatmeal (1/2 cup ): 13.5g – 2.2g = 11.3g
• Banana (1 whole): 27g – 3.1g = 23.9g
• Lentils (1/2 cup ): 19.9 g – 7.8 g = 12.1g
• Strawberries (1/2 cup ): 5.5g – 0.2g = 5.3g
• Apple (1 whole): 25g – 4.4g = 20.6g
• Almonds (1/2 cup ): 10g – 5.5g = 4.5g
• Blackberries (1/2 cup): 7g – 4 g = 3g

Processed Foods: Total Carb vs. Net Carbs Examples

Now let’s look at a couple of processed food labels.

One serve (1/2 cup) of these baked beans is 32 grams total carbs and 5 grams fiber, which equals 27 grams net carbs. No, this is definitely not a low carb food.

When you turn over to the ingredients list you will see there are 3 forms of “added” sugar in the product: white beans, water, sugar, brown sugar, bacon, salt, honey, mustard (vinegar, water, mustard seed, salt, natural flavor), modified corn starch, onion powder, caramel color, spices, garlic powder.

Remember, you don’t have to count sugar but you should always read nutrition labels to determine the quality of a food.

Let’s take a look at another low carb food product example: Atkins bars.

First, check out that long list of ingredients. A long list like this generally indicates a low quality food product. You will also notice ‘maltitol’ (a sugar alcohol), along with sucralose and acesulfame potassium (both artificial sweeteners).

Atkins market their product as “Net Carbs: 4 grams.”

So what they have done is take the total carbs and subtracted the fiber (5 grams) AND sugar alcohol (8 grams). But, what we just learned above is that only HALF should be subtracted, which would actually make this product 8 grams net carbs.

The maltitol this product uses has one of the highest glycemic indexes of 35, which means it will impact blood sugar to some degree. And artificial sweeteners can also impact blood sugar as well, along with having several other adverse effects on your health.

So the message here is: if you eat this food thinking it won’t influence your blood sugar, think again! You might be surprised that it has a bigger impact than expected.

Net Carbs vs Total Carbs: Pros and Cons

PRO: possibly eat a higher fiber diet.

At the very top, Kathleen said: “I eat a lot of veggies, which increases my total carbs to over 100 grams per day, but my net carbs are usually 40-60”

In this instance where Kathleen is obviously eating lots of natural whole food sources that are beneficial to her health, this would be acceptable because anything under 120 grams per day total carbs is technically considered ‘low carb.’ And she is consuming 40 to 60 grams of natural plant fiber, which also has huge benefits, including better blood glucose and A1c control.

Counting net carbs can be used as a method to tease out the carb-heavy foods that are completely off limits from the nutrient-dense vegetables and fruits that will nourish your body while keeping your blood sugar stable.

CON: possibly leads to eating more low carb “products”

But… if you’re eating lots of low carb “products” that are filled with “man-made” fiber and artificial sweeteners, preservatives, colors, etc. Well, you could technically argue that you’re still eating low carb. But, you’re not really going to be eating a healthy low carb diet.

If you eat a lot of processed and packaged foods, low carb or not, you’re basically eating a junk food diet. And quite simply, all those “man-made” ingredients just don’t have the same net effect on your metabolism as natural whole food sources do.

PRO: more food options

In a sense, a carrot isn’t technically a “low carb” food. One carrot contains 6.4 grams of total carbs, which isn’t as low as something like cabbage, which has just 2 grams per half cup shredded.

But that same carrot also provides 2.3 grams of fiber, reducing the ‘effective carbs’ to just 4.1 net carbs.

Obviously carrots are a whole food source that also provides ample nutrients and compounds such as carotenoids. Therefore, even though it is a little higher in carbs than other non starchy vegetables, it doesn’t make sense to exclude carrots from your diet.

So in a sense, calculating net carbs can open up your food options.

CON: net carbs not as accurate as total carbs

Because we can’t truly calculate the effect of the fiber and additional components of foods on blood sugar, A1c and insulin, overall, net carbohydrate counting is not as accurate as total carbs.

When you calculate total carbs you’re not going to have any discrepancies to counter for – sugar, sugar alcohol, fiber – it’s all going to be factored into your total carb count.

So What’s the Final Verdict: Should You Calculate Net Carbs or Total Carbs?

It can be a bit confusing because there is no clear and definitive answer on this. For the most part, research studies use total carbs, which suggests we should too.

However, we do know that the fiber component isn’t digested so really the net carb count is the amount of ‘digestible’ carbs – the net effect of the carbohydrate foods you eat.

The best answer is you can use both calculations to determine your daily carb intake. 

In terms of total carb intake, anything under 130 grams per day is considered low carb and will provide benefits. But the sweet spot for better blood sugar and A1c control seems to be around 50-80 grams total carbs per day.

And, you can also calculate net carbs to determine how much dietary fiber you’re eating. If you’re getting all (or at least most) of your fiber from natural food sources such as non starchy veggies, nuts and seeds, then having a total carb intake of 50-80 grams per day and a net carb intake of 20 to 60 just gives you another measurement of the healthiness of your diet.

Remember, the reason you calculate any numbers in the first place is so that you can gain better control of your diabetes/ prediabetes.

Numbers simply give you things to evaluate so you can tweak and change habits and improve your numbers and your health, which means both net carbs and total carbs can be useful measurements.

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