Total Carbs or Net Carbs
What Really Counts?

Defining Total Carbs, Net Carbs, Soluble & Insoluble Fibre

Should total carbs be considered when following a low-carb, ketogenic diet? Does eating fewer carbs always lead to better weight loss and improved health? Although most people still count net carbs (total carbs without fibre), the new trend within the low-carb community seems to be towards counting total carbs. Typically, people that count total carbs follow a very low-carb diet consuming 20 grams of total carbs or less a day. So, what is the right way to count carbs?

The main reason for this post was that many of my readers are convinced that counting total carbs and following a very low-carb diet is the ONLY way to go. Finding relevant information wasn't easy, as the effects of fibre on blood sugar and metabolic health are still a subject of research.

In short, net carbs are total carbs without fibre. There are two types of fibre: soluble and insoluble. The reason why most people use net carbs (aka available carbohydrates) is because they believe that dietary fibre doesn't affect blood sugar and our body cannot derive any calories from it. However, this claim isn't entirely accurate because it only applies to insoluble fibre which cannot be absorbed and has no effect on blood sugar and ketosis.

Dietary fiber is the indigestible portion of plant foods and has two main components: insoluble fiber (principally cellulose and lignin) and soluble fiber such as galacto-oligosaccharides and fructooligosaccharides (FOS), which are fermented by the gut microbiota into the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate. ( Flint et al. 2012)

Overview of Fibre in a Few Common Keto-friendly Foods

The Role of Soluble Fibre

Researchers have estabilished that our bodies can  derive calories from soluble fibre. However, when it comes to the effects of soluble fibre on blood glucose, it's more complicated. Studies show that soluble fibre can be absorbed and used for intestinal gluconeogenesis (IGN) which was thought to increase blood sugar and therefore affect ketosis. This potential ability of soluble fibre to affect blood sugar and therefore ketosis is the main reason why some experts and bloggers recommend using total carbs rather than net carbs.

How does it work? The short-chain fatty acids (SCFAs) propionate and butyrate, which are produced by fermentation of soluble fibre in the colon, activate IGN. While butyrate plays a role in enhancing energy expenditure, propionate enhances hepatic gluconeogenesis (release of glucose from the liver).

However, a recent study shows that soluble fibre helps, in fact, lower blood glucose. According to this this study, propionate can be used by the body for IGN and the overall effect of SCFAs through IGN is a net decrease in blood sugar. Unlike hepatic gluconeogenesis, IGN helps lower serum concentrations of glucose and improves overall glucose disposal. Commonly, increased production of SCFA is assumed to be beneficial by reducing hepatic glucose output and improving lipid homeostasis. (Weickert et al. 2008)

Additionally, when soluble fibre is fermented in the large intestine, it stimulates the release of gut hormones which play a role in inducing satiety ( Lattimer et al. 2010). As most of you may know, natural appetite suppression is the main reason people successfully lose weight on a low-carb diet.

Update: You can learn more about the role of soluble fibre in this post: Nuts & Seeds on a Ketogenic Diet

Bottom Line: Does soluble fibre raise blood sugar? Recent studies show that soluble fibre can, in fact, lower blood glucose levels. However, more studies are needed to understand the effects of dietary fibre on metabolic health.

Total Carbs vs Net Carbs. Ask Yourself: What Am I Trying to Achieve?

Should you count total or net carbs? It depends on what your goal is and how sensitive to carbs you are. Some people may be affected by the tiniest amount of carbs from berries while others can eat most foods without any issues.

I personally prefer using net carbs which is also reflected on my blog and in my apps. My main goal is to maintain my weight and manage my thyroid condition which I've been dealing with since 2011. You can read more about my diet here. When we created the KetoDiet iPad app, we focused on net carbs but also allow our users to check their total carbs count (see below).

In general, if you follow a low-carb / ketogenic diet to lose weight and improve your health, counting net carbs is a convenient way. In fact, high level of ketones / low level of glucose are not the most important factors in weight loss. Research simply doesn't support the idea that more ketones in your blood always lead to a greater fat loss. The most important factor in successful weight loss on a low-carb diet remains its appetite-suppressing effect.

In fact, you don't necessarily need to be in ketosis to lose weight or improve your overall health - there are other important factors to consider when your weight is stalling. Many studies that show improvements in both weight and health were performed on people eating even more than 50 g of total carbs a day.  This review and meta-analysis of clinical trials shows that not all of the studies were strictly focused on very low-carb, ketogenic diets throughout the whole trial.

Here are the most common reasons people follow a low-carb diet:

• weight loss (fat loss)
• improve overall health
• improve performance / increase lean mass
• manage a disease such as cancer, Alzheimer's, epilepsy or PCOS

Weight loss & health effects

Following a low-carb diet leads to weight loss in most cases but more ketones don't seem to adequately enhance weight loss. Accordingly, you don't need to follow a very low-carb diet (VLC) if your aim is to improve your health. Many people experience great benefits following the paleo diet with low-moderate carbohydrates.

Exercise & performance

The effects of the ketogenic diet on performance are described in Volek & Phinney's book devoted to low-carbohydrate performance. It's also worth checking Dr Peter Attia's website, Eating Academy. Your carb requirements and timing of carbs depend on the type of exercise. The general consensus is that if you mostly do weight training and cardio exercise, you can fully function on ketones and don't need any extra carbs. If, however, you do a lot of HIIT or Cross Fit, you may benefit from carb backloading, as the standard ketogenic diet may not be best for you.

Cancer management

Some people may follow a more restricted type of the ketogenic diet for therapeutic purposes. Ideally, the ketone level should be high while the blood sugar level should be low. Using total carbs and following a VLC diet may be a better way of counting carbs. You can find out more in our expert article on the effects of the ketogenic diet in patients with brain cancer.

What Do Experts Say?

There are differences of opinion even among experts not only whether to count total or net carbs but also regarding the "ideal" carb level. Dr Volek & Phinney suggest that ~ 50 g of total carbs a day is enough to induce nutritional ketosis. This is 20-35 grams of net carbs depending on the fibre content. Most people on a ketogenic diet successfully follow this approach.

This approach is different from Dr. Westman's approach suggesting that ~ 20 g of total carbs a day is what you should be aiming for. If you choose to follow a VLC diet, make sure you get sufficient micronutrients and include supplements, especially magnesium. You won't be able to eat avocados, some vegetables or psyllium husk powder unless you use very small amounts.

Should some healthy low-carb foods be avoided because they are high in total carbs? In fact, two thirds of the fibre in most foods is insoluble meaning it has zero effect on blood sugar and zero calories. As I mentioned above, although more studies are needed to understand the effects of dietary fibre on metabolic health, it seems that soluble fibre can, in fact, lower blood glucose levels. ( Lattimer et al. 2010)

Bottom Line: There is no "wrong" way, you can use either total carbs or net carbs. Choosing the "best" way for you depends on what you are trying to achieve by following the ketogenic diet.

Other Factors Which Play a Role in Weight Loss

Don't focus only on your carb intake. How about your protein or fat intake? It's a common misconception that you can eat an unlimited amount of calories and still lose weight. In fact, you can put on weight even on a low-carb diet. To avoid this mistake, you will need to understand a few basic principles and avoid common mistakes. Make sure you eat enough protein, not just fat - protein is the most sating macronutrient and will keep hunger at bay.

Low-carb ketogenic diets are naturally sating and act as appetite suppressants. This is why you'll eat less and won't need to count calories, which is one of the main effects of low-carb diets. In fact, to lose weight or/and stay in ketosis, you don't need to follow a VLC.

One of the common mistakes people make is that some people overeat dairy and nuts when they are trying to lose weight. You may experience weight stalling or even weight gain not because nuts and dairy will kick you out of ketosis but because these foods are calorie-dense and easy to overeat (100 grams of macadamia nuts have over 700 kcal and over 70 grams of fat!) There is no reason to avoid non-starchy vegetables such as broccoli, cauliflower, zucchini, bell peppers or fruits like avocado or berries. These foods are very high in micronutrients, low in carbs and won't impair your weight loss efforts.

If for any reason your weight is stalling for more than 2-3 weeks, you may need to consider keeping an eye on your energy intake (calories). Reaching a weight loss plateau may be caused by several factors and you don't necessarily have to be eating too much, in fact, you may discover that you haven't been eating enough. In my experience, losing body fat becomes more and more difficult as you get close to your target weight.

To make it easy for you to calculate your ideal macronutrients on a ketogenic diet, we developed a free online keto calculator, KetoDiet Buddy - try it now!

Ideally, you may also want to talk to an expert with experience in low-carb diets. My good friend, Franziska Spritzler, who is a low-carb dietitian, has great experience helping people lose weight and manage diabetes.

What to Be Careful About

1. Labels

No matter which path you choose, make sure you know how carbs are calculated where you live. In countries like US or Canada, total carbs as labelled include fibre - to get net carbs, you have to deduct fibre. Contrary to the US and Canada, in countries like UK or Australia, total carbs as labelled do NOT include fibre, which means they already represent what is known as net carbs in the US.

2. Low-carb Sweeteners

The vast majority of low-carb sweeteners are often advertised as "sugar-free", "carb-free" or "zero-carb". However, this is not always true. Some sweeteners like stevia, Erythritol or monk fruit extract contain very little carbs while others like Xylitol or Tagatose contain more carbs.

When using Swerve, Erythritol, Xylitol or sweeteners containing fructooligosaccharides (FOS), always remember to add carbs. What I've noticed is that some people subtract all low-carb sweeteners and count them as "zero" - this is not right. I have explained my "safe" method of calculating carbs in sweeteners here.

3. Products labelled "Low-carb"

Avoid most products labelled low-carb / zero-carb, etc. Atkins bars, Julian's Bakery bread and Dreamfields low-carb pasta are just some of the many products to avoid. They contain more effective carbs than the manufacturer claims and are often laden with unhealthy ingredients. I have written more about low-carb products in my post here.

To read more about carbohydrates on a low-carb diet, have a look at my two posts: All You Need to Know About Carbs and How Many Carbs per Day?