What Makes Fiber A Total “Myth”

One of the most eye-opening conversations I’ve had this year on the B.rad podcast was undoubtedly with Dr. Herman Pontzer. We talked about his fascinating work studying energy expenditure, and also his time studying the Hadza people in Northern Tanzania. Dr. Herman is hardly alone in his interest in the Hadza – these hunter-gatherers have been noted to have the “healthiest heart’s in the world” and are frequently subject to studies and observation because of their health and lifestyle.

Stanford University also did a study on the Hadza people that caught my eye recently, not just because it resulted in some pretty compelling findings, but also because one thing that stood out to me was their interpretation of the role fibrous foods play in the typical Hadza diet.

This conclusion didn’t come out of nowhere. A Stanford Professor did specifically mention fiber in his statement about the study, commenting that, “The Hadza get 100 or more grams of fiber a day in their food, on average. We average 15 grams per day.” But the problem is that everything about this assumption – that a high fiber diet is the key to having a healthy microbiome, and that eating a lot of fiber is one of the reasons why the Hadza are so healthy – is incorrect. It’s also not exactly groundbreaking to state that the average American isn’t nearly as healthy as someone who lives a traditional hunter-gatherer lifestyle…that’s just a given in most cases.

This conclusion didn’t come out of nowhere. A Stanford Professor did specifically mention fiber in his statement about the study, commenting that,“The Hadza get 100 or more grams of fiber a day in their food, on average. We average 15 grams per day.” But the problem is that this assumption – that a high fiber diet is the key to having a healthy microbiome, and that eating a lot of fiber is one of the reasons why the Hadza are so healthy – is incorrect. Not to mention the fact that it’s hardly eye opening to compare the diet of the average American to someone who lives their life in the traditional hunter-gatherer style! 

Ultimately, what is really alarming about these headlines is that the real truth is that fiber, as Dr. Paul Saladino has said on the B.Rad podcast before, is actually a total “myth.”

But what makes fiber a myth? Let’s take a quick look back into the history of this idea that extra fiber = good for you. This idea can actually be traced back to the 1950s, when a British surgeon named Denis Burkitt traveled to Africa, and noticed that locals did not have the same occurence of diverticulosis that was plaguing Britain at the time. So, Dr. Burkitt decided that that automatically meant fiber was the key to good health – but this was, unfortunately, all merely based on his observations (not scientific studies) of locals and their diets. And while he did end up identifying some other important dietary differences between Africans and Westerners (essentially, no processed food and higher animal fat consumption), he incorrectly gave all the credit to this supposed higher fiber intake. He even wrote a best-selling book about it, and since Dr. Burkitt was a respected doctor, the great myth of fiber just continued to snowball from there. More than 50 years later, it’s still prevalent – perhaps even more than ever, thanks to the popularity of plant-based diets in recent years.

But the risks that come with consuming plants are clear now, and have been for some time. Dr. Paul Saladino has described it perfectly: “Plants cannot run away, or bite or claw their way to freedom. Plants want to survive and reproduce, and therefore, they developed a variety of toxins to protect themselves from being eaten.” 

I also had a deeply insightful conversation with Dr. Al Danenberg on B.Rad about fiber. Dr. Al revealed: “You do not need fiber from plants to have a healthy gut microbiome, and you don’t need fiber motility in the gut to have healthy bowel movements, because a lot of the motility in the gut is related to the mass cells that are within the system’s epithelial barrier that are communicating back and forth.” He went on to add: “Everything I know and I’ve read and personally experienced is that an animal-based diet is not only ideal for the human species, but it feeds our microbiome impressively.”

Serious misinterpretations of various studies aside, it’s also important to add that the Hadza also eat seasonally, and that their diet, while it does include some plant foods, doesn’t actually extend to plant foods like vegetables and leafy greens — it’s actually mostly just fruit, specifically berries and baobab, as well as honey and tubers (the Hadza eat five categories of food: meat, berries, baobab, tubers, and wild honey). As I’ve mentioned before, fruit is actually considered fine on a carnivore diet (depending on the individual, of course), because as the final offering of the plant, it has less defenses (aka toxins), and is therefore easier for your body to digest. I have personally found it best to enjoy fruit seasonally and to never go looking for anything that’s out of season (for example, tropical fruits, like pineapples and mangos, actually regulate your body temperature in hot weather and cool your body down – not exactly something you need in the middle of winter!). 

If you’re thinking about reducing your plant and fiber intake, it’s possible that your decision may be met with some skepticism, judgement, or flat-out confusion. In case that does happen, here are just a few compelling studies and research-backed facts about fiber I’ve learned (and please feel free to share this if you have any bloated friends who need some convincing, as well as relief!):

1) Stopping or reducing dietary fiber intake reduces constipation and its associated symptoms, according to a 2012 study.

2) One study found high fiber diets do not actually protect against asymptomatic diverticulosis.

3) One woman actually developed acute kidney injury that progressed to end-stage renal disease, all from adhering to a Green Smoothie Cleanse (aka, nothing but fiber!).

4) One study, “Myths and Misconceptions About Chronic Constipation,” found that “many patients with more severe constipation get worse symptoms when increasing dietary fiber intake.” Another study focusing on the mortality rates of British vegetarians came to the same conclusion.

The results of these studies are hardly surprising to me when I think back to how I felt every single time after drinking a green smoothie every morning. Now that I’m more than two years into a devoted carnivore eating pattern, I can see clearly why: a mixture of various greens like kale, celery, and spinach, blended up with various superfood powders and almond milk, while offering some calories for energy, simply doesn’t give you much from a nutritional standpoint. To top it off, then your system has to deal with all these concentrated plant poisons! No wonder I ended up quitting the green smoothie game shortly after – the bloating and gas, aside from being super uncomfortable, was a clear signal from my body that it was not getting the fuel it needed to thrive.

I’m also happy to report that these days, I am actually back to enjoying a morning or mid-afternoon smoothie (click here to read the blog post where I talk about my My New Diet). And while it may surprise you, my smoothies actually do still contain a little bit of fiber (usually in the form of some frozen berries). But, they also include true superfoods like grass-fed liver, organic pastured egg yolks, collagen, and even freeze dried organ meat capsules! It may sound out there, but the flavor is good (seriously!), the nutrient content is sky high, and it keeps me full for hours (with zero bloating and gas, I’ll add). Don’t knock it until you’ve at least tried it once! 

However, if you are feeling a little hesitant to start chucking frozen liver chunks into your smoothie, but still want to up your organ meat game, there are tons of recipes online and in cool carnivore and keto cookbooks that will make cooking organ meats a lot easier (and a lot more appetizing!). And to make sure you are eating above the steak line, check out the Carnivore Scores guideDr. Kate Cretsinger and I created this in the hopes of simplifying and clarifying any and all dietary questions when it comes to carnivore style eating, and it’s also a great introduction and guide to what is ultimately a very rewarding, enjoyable, and deeply satisfying diet. Plus, you may be surprised by the amount of variety in the food choices, as well as which plant foods are actually included on this list! Click here to get the Carnivore Scores chart.



Brad Kearns
Brad Kearns
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