Unpopular opinion: Is Fiber Overrated?
This may ruffle a few feathers..
I know this post may be controversial, but I am going to write about it anyways. And what’s a little controversy every once in a while…
One year ago, when I decided to take on the challenge of World Carnivore Month, I did get the side eye from many people. There were many questions and one that I got a lot was - ‘But what about fiber?
What About Fiber?
Doctors, dieticians, nutritionists and health coaches alike preach the importance of daily fiber in our diet. The recommended daily allowance - which is really the bare minimum for health - is 25g for females and 38g for males, approximately. This can vary with age as well. But when someone is eating just meat or animal based foods such as dairy, and eggs, there is no fiber being digested. So how does one poop?
Well, the human body still has the mechanisms to expel waste products, because it isn’t the fiber that is making us poop. It is the intestinal muscles that contract to keep food moving through our system. Our bodies digest and absorb what we can and then the rest is waste to be eliminated. The fiber just adds bulk and is said to help remove toxins.
But we have been told that fiber is essential and we require it for healthy body functions. But do we? So this got me thinking, when did the history about fiber being important to our health begin? They didn’t teach the history of fiber in nutrition school, they just told us it was necessary for digestive health.
The History of Fiber
Fiber as a health tool entered the conversation in the mid 20th century (1940’s to 1960’s) but it wasn’t until the early 1970’s when an English doctor, Denis Burkitt, and others, brought it to the forefront of health. He was working in Africa and noticed diseases such as colon cancer, heart disease and diabetes were rare among the high fiber, plant based diets. Burkitt along with many other doctors published various papers concluding fiber deficiency ‘may protect against diverticular disease, appendicitis and cancer of the colon’. By the late 1970’s committees in the US started to recommend more fiber rich foods based off these papers. This recommendation became the backbone for marketing strategies of the cereal companies who marketed bran as a health food. And fiber was the ingredient needed to combat constipation, heart disease and cancer. With more studies being done every day on the use of fiber, these claims are getting ‘murky’ and maybe fiber isn’t the remedy it is made out to be for our health.
FACTS:
For young adults less than 50, colon cancer rates are rising. From 2012 to 2021, they are rising at 2.4% per year and we have been seeing this trend gradually increase since the 1990’s. The American Cancer society now states that colon cancer is the leading cause of death for men under 50 and the second cause of death for women under 50.
And between 1999-2020 among 15-19 years old’s, there is an increase of 333%, and 185% for 20-24 year old’s. Absolute numbers are definitely not as high as older populations but very concerning as to why teens and young adults are being diagnosed with this disease.
This is not just unique to the US, on average countries like New Zealand, Chile, Puerto Rico are also seeing a rise in cases.
IBD’s (inflammatory bowel disease) such as Crohns and Colitis are growing with approximately 70,000 to 80,000 newly diagnosed cases expected in 2025 in the US and many of these will be children. In North American 6-11 per 100,000 children are being diagnosed with Crohns, more notably in Canada. Globally all cases are rising as well.
As per the CDC:
But fiber is supposed to reduce our risk of these diseases, and our fiber consumption is higher then ever before, then why are these health issues increasing? We get fiber from vegetables, fruit, whole grains, supplements. The message is everywhere.
“Are you getting enough fiber”. "
“How to get more fiber in your diet”
“Easy and delicious ways to get more fiber in your diet”
Definition of Fiber
So what exactly is fiber? AKA dietary fiber. Fiber is the structure of plants. Simple as that. There are 2 types:
Insoluble - this is the fiber that we can not digest and passes through our digestive system unchanged. This is what provides the bulk and are told this is what sweeps up toxins, excess cholesterol and eliminates it.
Soluble - this is the fiber that absorbs liquid like pectin or psyllium and softens your stool. It also feeds our gut bacteria.
What does Fiber Do?
Fiber in our diet, in some cases, has been shown to relieve constipation, lower risk of hemorrhoids, diverticulitis, colon cancer and other diseases of the colon, lower cholesterol levels and balance blood sugar. It has also been known to help you lose weight by making you feel full. Best sources of fiber are of course plant based foods such as vegetables, fruit, whole grains, bean, nuts and seeds. But many get it as a supplement such as metamucil or benefiber which is a wheat dextrin or psyllium husk. Heck, you can even get fiber gummies.
Fiber also helps feed our gut microbiome, the bacteria that lives in our gut to help digest food. There are different bacteria in our gut that feeds on different foods, not just plant foods. Some bacteria feeds on protein as well. In a study on diet and the microbiome, the findings show that the gut microbiomes can switch between a herbivore diet and and carnivore diet reflecting food that are available. Think of ancestrally, there were times when plant foods may not have been available such as the Inuit population in the far north hemisphere where their diets consisted of meat and fat until summer when berries and other foods might be accessible.
Fiber is also found to help create ‘butyrate’ - a short chain fatty acid. Butyrate is produced by the colon bacteria to nourish and protect the gut from inflammation. But this fatty acid is not just produced by consuming plant fiber to feed the bacteria to produce it. It is also produced by bacterial fermentation of protein. Butyrate molecules are almost identical to ketones (ketones are the acids our bodies make when we use fat for energy instead of glucose). Ketones are even more potent anti inflammatory properties than butyrate. So for those on a ketogenic diet, and are not getting in the required amount of fiber, the circulating ketones protect your colon cells. It is also known that the intestinal wall actually replaces itself every 3-4 days.
Diet rapidly and reproducibly alters the human gut microbiome | Nature
The effects of exogenous ketones on biomarkers of Crohn’s disease: A case report.
The Cons to Fiber
There are some consequences to fiber intake. Fiber has been shown to interfere with the absorption of certain nutrients especially calcium and iron. But can also affect zinc, magnesium, B6 and hormone metabolites estrogen, progesterone, testosterone, LH and FSH. Unfortunately when the fiber ‘pulls’ out toxins, it attracts nutrients as well.
Most high fiber foods are carbohydrates and some are known to cause spikes in insulin and GLP-1 leading to an increase in hunger rather then a decrease.
Excessive fiber intake can cause digestive discomfort, excessive gas, bloating and cramping.
Carnivore Diet and Fiber
So this takes me back to eating a carnivore-ish diet. If you have been reading my newsletters for a while, you will have followed me as I changed to eating an animal based carnivore diet (meat, eggs, dairy, fruit) about 85% of the time. So I am getting some fiber in my diet but not to the extent of what is recommended. And yes, I am still pooping. Maybe not 3 times a day or everyday but I still remove waste. When a person eats more carnivore, keto, or meat based, most of the protein is digested and nutrients absorbed into the body, leaving minimal waste. There is no undigestible insoluble fiber to be eliminated.
You may be saying, ‘But all the studies..??’ Yes there are lots of studies that conclude the benefit of fiber, but there are also studies that do not conclude fiber is the benefit. One thing to remember when it comes to nutrition and studies. Conclusions are never absolute and ‘Causation does not always means Correlation’. Nutrition studies on humans are mostly done through epidemiology studies. Done by observation and questionnaires and conclusions are based on the analysis of patterns and interpretation.
So in a society where high fiber intake is expressed by the mainstream medical and health establishment, why are these gastrointestinal diseases still rising? Maybe we should be looking at other causes? Is it the oxidized oils, sugars, chemical additives and preservatives added to foods? These ingredients has increased immensely since the 1970’s and are also inflammatory to our gut and are a big factor in degrading the mucus layer of our intestines causing a breakdown of protection.
And although anecdotal, there are thousands of people who are actually seeing significant improvements or erasing their gut disease by going on a carnivore or keto diet and eating little to no fiber.
By no means am I saying the fiber is BAD. I think it has shows great results in balancing blood sugar when you eat it with something sugary, like an apple. It just might not be the answer to all the problems they say it is. And maybe we should look to focus our efforts in another direction.
Thoughts?
Danni
Sources:
The Carnivore Code - Dr Paul Saladino, MD
Toxic Superfoods - Sally K Norton, MPH
The Carnivore Diet - Dr. Shawn Baker, MD
Change Your Diet, Change Your Mind - Georgia Ede, MD
Very interesting post! I remember a few years ago there was a high fiber diet trending with celebrities, and I saw reports of people experiencing stomach pain when they tried this diet. For me, the everything in moderation approach works. I definitely experience GI issues when I eat too much or too little fiber.
I find myself increasingly coming round to the idea that fibre is most definitely overrated. It can be coarse and irritating to the gut, and many clients find relief from IBS by reducing fibre or breaking it down through cooking. Those on raw plant foods seem to suffer the most.