We’ve all been told to increase our fiber intake. That it stops our GI tract from getting clogged up, prevents weight gain, and somehow prevents us from getting colon cancer. What if I told you none of this was true?

Let’s take it back to the beginning

A man named Peter Cleave developed a hypothesis: the saccharine-disease hypothesis. Basically, he looked at the increase in diseases of western civilizations, including cancer, diabetes, and heart disease, within various cultures. He noticed that the rates of these diseases correlated with an increase in sugar intake within those populations. The more sugar that was consumed, the more prevalent the diseases were.

So he was saying sugar was the bad guy in all of this

Unfortunately, for him, he developed this theory in an era when there was only room for one bad guy and that bad guy was FAT, and the associated increase in cholesterol from ingested fat. His theory didn’t play nice with Ancel Key’s heart health hypothesis, so no one listened to Peter Cleaves.

A man named Denis Burkitt knew of Cleaves’ hypothesis and did something simple to adapt the hypothesis to fit the current narrative that Keys had instituted. Since Cleaves’ hypothesis blamed diseases of western civilization on the increased intake of simple sugar and refined grains, he just replaced the causal agent from increased sugar intake to a decrease in fiber consumption. This logic works because when you refine carbohydrates, you take out most of their fiber content. Think of white bread versus whole grain bread. The white bread is more processed, therefore has less fiber content, and the whole grain bread is less refined, consisting of more fiber in comparison. 

This idea took off quickly because it fit the mold that Ancel Keys had laid out. It also meant an increase in consumption of grains, legumes and vegetables in order to be healthy, which also fit the low fat narrative. 

Unfortunately, for the rest of the world, there was never any hard data at the time to justify this claim. The hard studies that did come out much later showed that fiber wasn’t all that it was cracked up to be.

“New England Journal of Medicine editorial that accompanied back-to-back April 2000 reports on two major trials—one on fourteen hundred subjects of the Phoenix [Arizona] Colon Cancer Prevention Physicians’ Network, and one $30 million trial from the National Cancer Institute—both of which confirmed that fiber had no effect on colon cancer.”¹

So the cancer claims didn’t pan out

What about the weight management claims? Burkitt’s argument revolved around the calories in, calories out, model. If you’ve read the article on calories in, calories out, then you know this is complete crap. But just for giggles, I’ll add this quote from one of Burkitt’s cohorts:

“To explain how obesity could be induced by the fiber deficiency of modern refined-carbohydrate foods, Trowell reasoned that the causal factor was an increased ratio of energy to non-digestible fiber in the Western diet. Ninety-three percent of the nutrients in a typical Western diet were available for use as energy, Trowell calculated, compared with only 88 or 89 percent of those in a typical primitive diet containing copious vegetables, fruits, and wholemeal bread. The lower figure, Trowell wrote, is “the figure that is the natural, inherited evolutionary figure.” Over the course of a few decades, he said, we would unknowingly eat 4 percent more calories than would be evolutionary appropriate and therefore gain weight.”²

Anyone using the calories in, calories out concept to justify weight gain obviously has no idea how our metabolism works. We truly have very little impact on our total energy expenditure. And a measly 4 percent wouldn’t cause any dramatic weight gain in any of us.

“The key point here is that total energy expenditure is not the same as exercise. The overwhelming majority of total energy expenditure is not exercise but the basal metabolic rate: metabolic housekeeping tasks such as breathing, maintaining body temperature, keeping the heart pumping, maintaining the vital organs, brain function, liver function, kidney function, etc. Let’s take an example. Basal metabolic rate for a lightly active average male is roughly 2500 calories per day. Walking at a moderate pace (2 miles per hour) for forty-five minutes every day, would burn roughly 104 calories. In other words, that will not even consume 5 percent of the total energy expenditure. The vast majority (95 percent) of calories are used for basal metabolism.”⁴

So there goes the weight management claims

Okay, okay. But what about protection from constipation?? For some reason, everyone seems to believe this about fiber. I’ll break it down like this: think of our GI tract like the toilet in your house. If you wanted to clog your toilet, what would you do? Stuff a ton of toilet paper down it, right? That’s exactly what’s happening with fiber. Constipation is the presence of too much bulk in your intestinal tract, not too little. Why would you want to add more?  The only reason fiber can sometimes increase transit time through our intestines is because fiber acts as an irritant to our intestines, causing them to release mucous to mitigate some of the negative effects of fiber and get it out of our intestines as soon as possible. This has skewed the nations idea of what “normal” digestion should be. In terms of transit time, frequency and stool volume. It’s true fiber can speed up food transit time, but I argue that isn’t a good thing. Wouldn’t you want your body to break down the food you eat completely in order to get all the possible nutrients out of it? Especially if you’re eating healthy and spending good money on high quality meats, for example. As stated here, fiber can be placed in the same category as a phytate, which robs us of vital nutrients in our food.

“But fiber also has a little-known dark side as far as nutrition is concerned. Fiber can bind with nutrients and actually remove them from the body before they have chance to get absorbed… Here’s how it works in a simplified way: Both fiber itself and a constituent called phytic acid or phytate, are extremely effective at “locking onto” dietary minerals.”³

So there goes the constipation claims as well

Man, almost seems like fiber is completely non-essential. Eat at your own risk, folks.

REFERENCES

1. Taubes, Gary. Good Calories, Bad Calories (Kindle Locations 2890-2895). Knopf Doubleday Publishing Group. Kindle Edition. 
2. Taubes, Gary. Good Calories, Bad Calories (Kindle Locations 2829-2830). Knopf Doubleday Publishing Group. Kindle Edition.
3. Wright. Why Stomach Acid Is Good for You: Natural Relief from Heartburn, Indigestion, Reflux and GERD (p. 80). M. Evans & Company. Kindle Edition. 
4. Fung, Jason. The Obesity Code: Unlocking the Secrets of Weight Loss (p. 52). Greystone Books. Kindle Edition.