For years we’ve been told the same thing: eat more fibre. It’s good for digestion. It keeps you regular. It’s essential for gut health. Or so we’re told. 

Fibre has become one of those nutrition rules that almost no one questions. But what if that advice isn’t as solid as we thought? What if it's just another one of those myths that we’ve all believed?

In recent years, Keto, Carnivore, and even Low-Carb diets have challenged us to look at fibre in a new way. And what many people are discovering is surprising: you don’t actually need fibre to be healthy.

Where the fibre rule came from

This push for fibre came from the same era as the high-carb, low-fat dietary guidelines (the ones that have very recently changed. Because grains were the foundation of the recommended diet, promoting fibre as a nutritional need helped push those grains. 

Grains were labelled “healthy” because they contained fibre. Cereal was marketed as good for digestion, and things like breads and pasta were good for you because everyone needs fibre, right? 

But the problem is that much of the evidence for fibre is observational, and you have to remember that correlation does not equal causation. Just because someone eats more fibre and has good health outcomes, that does not mean it’s the fibre giving them those outcomes. You have to look at what else those people are doing, such as exercise, hydration, and eating whole foods. 

Is fibre required for digestion?

One of the biggest myths about fibre is that it prevents constipation. In reality, for many people, fibre does the opposite. 

Fibre adds bulk, but bulk isn’t always a good thing. For sensitive guts, fibre can increase bloating, gas, and pain. This is why people with IBS are often told to reduce fibre, not increase it. If fibre truly helped with digestion, don’t you think IBS sufferers would be told to eat more of it?

Constipation is not always a fibre problem. It can be a hydration issue, an electrolyte issue, or a reaction to foods that irritate the gut. Adding more rough material to an already irritated digestive system doesn’t fix the problem.

Besides all that, sometimes what we think is constipation isn’t really constipation anyway, it’s just going less frequently, for one reason or another. 

What Keto and Carnivore have shown us

Keto and Carnivore diets are naturally low in fibre because they don’t contain much plant material. Carnivore contains almost none. 

And yet, thousands of people report normal, comfortable digestion on these diets. Some even say it’s the best their digestion has ever been. Less bloating. Less gas. Less discomfort. Even when people don’t go as often, they still feel good. 

This doesn’t happen because digestion shuts down without fibre. It happens because the gut no longer has to deal with foods that cause irritation and inflammation. 

What these diets have clearly shown us is that your digestive system can function just fine without plant fibre when it’s supported by healthy fat, protein, and hydration. Don’t believe it? Go eat some butter (a healthy fat), and see how fast you go to the bathroom. 

But what about the microbiome?

This is where the whole fibre debate usually gets most heated. We’re told that the microbiome will suffer without fibre, that it’s needed to feed gut bacteria. But gut bacteria is adaptable, and it doesn’t just survive on fibre. It also uses amino acids, fats, and compounds from animal foods. 

Research suggests that the gut microbiome shifts based on what you eat. It doesn’t just disappear because you reduce fibre. It changes. 

A healthy gut microbiome isn’t just defined by how much fibre you eat. It’s defined by how well your gut functions, and if your gut is sensitive to plant material (and maybe even if it’s not), loading up on fibre is not helpful. 

So do you actually need fibre?

The honest answer is: it depends on the person. 

Some people feel fine eating fibre, but many people feel much better without it. And there’s no real, scientifically proven requirement that says humans must eat fibre to be healthy. 

Fibre is not an essential nutrient. You cannot be deficient in it. They don’t run blood tests to see how much fibre you have. That alone should make you rethink the fibre myth. 

Bottom line

Fibre is optional, not mandatory. 

If you feel good eating fibre, we’re not here to tell you to stop having it. But if fibre makes you feel bloated and uncomfortable, you don’t need to force it just because of some outdated nutrition rules. 

Your body, and how you feel, is the best feedback system you have.