Episode 114
Keep Your Poop in a Group
Why Fiber Fails to Impress—and Why That’s the Point
Fiber has a public relations problem. Unlike supplements or extreme diets, fiber does not promise instant transformation. Instead, it works slowly, predictably, and quietly. Because of that, people rarely notice it when it’s doing its job well. However, that very boredom is precisely why fiber matters.
When fiber intake is adequate, digestion functions normally, blood sugar behaves more consistently, and bowel habits stay predictable. As a result, there is no drama to post on social media. Consequently, influencers move on. Meanwhile, the science stays exactly where it has been for decades: fiber lowers disease risk over time.
That kind of quiet effectiveness may not sell products, but it saves lives.
“Fiber Isn’t Essential”—Why That Argument Misses the Mark
Technically speaking, fiber is not an essential nutrient in the classic sense. In other words, there is no disease caused solely by a lack of fiber the way scurvy results from vitamin C deficiency. Because of this, critics often stop the conversation there.
However, medicine does not ask only whether you survive. Instead, it asks whether your risk of chronic disease rises or falls over time. On that front, fiber consistently lowers the risk of colon cancer, improves glucose regulation, reduces constipation, and supports cardiovascular health. Therefore, while you can live without fiber, you do not age particularly well without it.
Protein Gets the Spotlight While Fiber Does the Work
At the same time, nutrition conversations fixate on protein. Protein goals dominate podcasts, social media, and supplement aisles. Yet, in practice, true protein deficiency in the United States is rare, even among bariatric surgery patients.
In contrast, fiber deficiency is the norm. Roughly 92% of Americans fail to meet recommended fiber intake. As a result, constipation becomes common, long bathroom visits feel normal, and scrolling on a phone in the bathroom gets rebranded as “self-care.” Unfortunately, that normalization hides a real problem.
A Personal Lesson From Oats, Gas, and a Scorched Desk
Years ago, I learned a fiber lesson the hard way. After deciding to increase my fiber intake quickly, I started eating steel-cut oats every morning during a busy meeting week. At first, everything seemed fine. Soon, however, my digestive system made it clear that it had not been consulted in this decision.
By the second day, bloating appeared. By the third day, office etiquette became questionable. Consequently, I lit a candle at my desk. Unfortunately, I turned my back, and papers caught fire. Although the flames were extinguished quickly, the scorch mark stayed for years.
That stain served as a reminder: fiber works best when introduced gradually. Your gut adapts over time. Confidence without patience, on the other hand, leads to unnecessary consequences.
Not All Fiber Works the Same Way
Understanding fiber helps people stop fearing it. Soluble fiber, found in oats, barley, beans, lentils, psyllium, apples, and citrus, forms a gel in the gut. Because of this, it slows absorption, reduces glucose spikes, and lowers LDL cholesterol. Consequently, psyllium appears in clinical guidelines rather than influencer protocols.
Meanwhile, insoluble fiber focuses on mechanics. It adds bulk, speeds transit, and improves regularity. Importantly, this matters even more for people using GLP-1 medications, where slowed digestion often leads to constipation. In that setting, fiber is not optional—it is foundational.
Finally, fermentable fiber feeds gut bacteria. Beans, onions, garlic, asparagus, chicory root, and resistant starch nourish beneficial microbes. As these bacteria grow, they produce short-chain fatty acids, especially butyrate, which supports gut barrier function and immune regulation.
No, Butter Is Not a Shortcut to Butyrate
Despite what circulates online, butter does not meaningfully deliver butyrate to your colon. Although butter contains trace amounts of butyric acid, that fat is absorbed in the small intestine long before it reaches the colon. In contrast, the butyrate that protects colon health is produced by bacteria fermenting fiber directly in the colon.
Therefore, if butter were an effective therapy, gastroenterologists would prescribe croissants. They do not.
Supplements Help—but Food Still Wins
Fiber supplements can be useful. Psyllium and methylcellulose typically provide four to five grams of fiber, which helps people start. However, that amount represents only about ten percent of a reasonable daily target.
Personally, I use Loam, which provides around twelve grams of mixed fiber in a smoothie. Nevertheless, supplements act as bridges, not destinations. Ultimately, food does the heavy lifting.
IBS, FODMAPs, and Why We Avoid Diet Cosplay
Some people with IBS feel worse when fermentable fiber increases too quickly. Because fermentation produces gas, symptoms can flare initially. For that reason, clinicians use FODMAPs as a temporary elimination tool to identify triggers.
However, elimination is not the end goal. Instead, we reintroduce foods within a Mediterranean dietary pattern, which promotes diversity and tolerance. In contrast, Whole30 markets itself as elimination but functions primarily as low-carb restriction. That approach avoids symptoms rather than solving them.
What Eating Enough Fiber Actually Looks Like
People do not eat grams of fiber. They eat meals. A Mediterranean-style day, such as the 3-Day Mediterranean Diet at terrysimpson.com, delivers fiber incidentally.
Breakfast often includes oats, berries, and nuts. Lunch typically features vegetables, legumes, whole grains, and olive oil. Snacks rely on fruit, nuts, or hummus. Dinner centers on vegetables, whole grains like farro, and fish or poultry. Over the course of a day, fiber naturally reaches 25–40 grams without spreadsheets or stress.
Start Slowly, Then Stay Consistent
If you currently eat little fiber, the solution is simple but not dramatic. Increase intake gradually. Drink water. Give your microbiome time to adapt. Although you are not fragile, abrupt change can still cause discomfort.
The Bottom Line
Fiber does not need hype. Instead, it needs consistency. It works quietly, steadily, and reliably. If bathroom visits require entertainment, the issue is not age—it is fiber.
Transcript
>> Dr. Terry Simpson: M Today, we're going to talk about poop. Keep your
Speaker:poop in a group. Get your together. All right,
Speaker:we're going to talk about fiber. And before you
Speaker:turn this off, a fair warning. There will be a few
Speaker:dad jokes today, because every dad needs a dad
Speaker:joke or two. And if you can't laugh while learning
Speaker:about digestion, you're taking life and yourself a
Speaker:little too seriously. Now, fiber is about poop,
Speaker:but it's also about a lot more than poop. It's
Speaker:about lowering your risk of colon cancer. It's
Speaker:about smoothing glucose spikes. It's about
Speaker:avoiding hemorrhoids, diverticulosis,
Speaker:diverticulitis, and spending less time in the
Speaker:bathroom wondering if the phone is about to fall
Speaker:into the toilet. I know you've had it happen. I
Speaker:saw. And by the way, that's not a productivity
Speaker:issue. It's a fiber issue. When I run into the
Speaker:true carnivores and they always identify
Speaker:themselves immediately, they are very eager to
Speaker:tell me fiber is not an essential nutrient. And
Speaker:technically, they are correct. There is no classic
Speaker:fiber deficiency disease, no scurvy of spinach, no
Speaker:berry berry of bran. But medicine isn't just about
Speaker:what kills you quickly. It is about what breaks
Speaker:systems down slowly. And here is the part that
Speaker:never gets mentioned. I hear influencer after
Speaker:influencer obsess about protein, protein goals,
Speaker:protein timing, protein powders with names that
Speaker:sound like Marvel villains. And yet true protein
Speaker:deficiency in the United States, even among
Speaker:bariatric surgery patients, is rare. But 92% of
Speaker:Americans do not get enough fiber. 92%. And that
Speaker:lack of fiber is exactly why some people are stuck
Speaker:on the toilet with the latest squatty, potty
Speaker:scrolling, waiting, hoping, maybe even listening
Speaker:to my podcast, but quietly increasing their risk
Speaker:of rupturing a diverticulum or developing worse
Speaker:hemorrhoids. So today on 4Q, we are going to make
Speaker:sense of the madness of fiber. I am your Chief
Speaker:Medical Explanationist, Dr. Terry Simpson, and
Speaker:this is 4Q Fork University, where we bust a few
Speaker:myths, make sense of the madness, and teach you a
Speaker:little bit about food and medicine. Let me tell
Speaker:you a story about oats. Everyone except a few
Speaker:rubbish people agree that oats are healthy. The
Speaker:vast majority of literature shows that people who
Speaker:eat oats have less obesity, less diabetes, smaller
Speaker:circumference of their waistline. And everybody
Speaker:knows that oats have fiber. And steel cut oats
Speaker:probably have the most fiber. Well, groats have
Speaker:the most fiber, goes groats, steel cut oats,
Speaker:rolled oats, instant oats. But so One week, I
Speaker:decided to be very responsible and increase my
Speaker:morning fiber. Now, this was many years ago when
Speaker:I, um, was not so sophisticated about all this
Speaker:stuff. And I was in meetings all that week with
Speaker:colleagues. And every morning there was coffee and
Speaker:steel cut oatmeal. And they made it deliciously
Speaker:steel cut. It was nutty. It was delicious. So I
Speaker:joined in. Day one, fine. Day two, my bowels
Speaker:started getting the message. I was full. I was a
Speaker:little bloated. I was a little m expressive. By
Speaker:the time I got back to my office, this was no
Speaker:longer subtle. So I did what any reasonable
Speaker:physician would do. I opened a window and I lit a
Speaker:candle. I had one of those big old school desks,
Speaker:papers everywhere, large oak frame. And then I got
Speaker:a phone call. And I turned my back on the desk
Speaker:while I was answering the phone call. When I
Speaker:turned around, some papers were on fire and I had
Speaker:to put it out. And for years, that dark scorch
Speaker:mark on my desk reminded me of a very important
Speaker:lesson. Do not jump from low fiber to high fiber
Speaker:overnight. Your gut needs time to adapt. And yes,
Speaker:my desk paid the price for my confidence. That's
Speaker:why it's called a trial by fiber.
Speaker:>> Dr. Terry Simpson: Hi, it's producer Ivo jumping in here, saying I
Speaker:had no advance warning of any of this.
Speaker:>> Dr. Terry Simpson: All right, so what does fiber actually do? Or as
Speaker:some might say, what does fiber does? Fiber is a
Speaker:carbohydrate that humans don't digest. So you
Speaker:would never count it as a part of the fiber if
Speaker:you're counting carbs, which you shouldn't be, but
Speaker:you would never count it for added sugar. But
Speaker:there are different types of fiber. Okay, so we're
Speaker:going to go over this. It's not that boring, I
Speaker:promise. I want you to think of soluble fiber like
Speaker:the oats that I had. Barley beans, psyllium. And
Speaker:they form a gel in your gut. This gel slows
Speaker:absorption, which means that the glucose isn't
Speaker:absorbed as rapidly, so the glucose doesn't spike.
Speaker:And because your liver makes cholesterol, how it
Speaker:gets your cholesterol into your bloodstream is it
Speaker:dumps the cholesterol into your bile, which goes
Speaker:into your small bowel.
Speaker:>> Dr. Terry Simpson: And.
Speaker:>> Dr. Terry Simpson: And when you have fiber, it absorbs some of that
Speaker:cholesterol, which is why fiber lowers your low
Speaker:density lipoprotein cholesterol. And that, by the
Speaker:way, is why psyllium shows up in all the clinical
Speaker:guidelines. Now, insoluble fiber is simpler. This
Speaker:is what. Well, we'll call it the make your poop
Speaker:better fiber. It adds bulk, it speeds transit, and
Speaker:it makes things predictable. It also does the
Speaker:opposite. So if you have really loose stools,
Speaker:let's say you ate something you shouldn't have or
Speaker:have a little bit of distress fiber will actually
Speaker:help you. People who have problems with bile,
Speaker:salt, diarrhea, we put them on a higher fiber
Speaker:diet. People who have fatty diarrhea or other
Speaker:things, we put them on a higher fiber diet. But
Speaker:here's the thing. If you're on a GLP1, I am, for
Speaker:example, and you're constipated, I am not. You
Speaker:need to have fiber in your diet. Magnesium gummies
Speaker:are not a long term bowel plan. They're a side
Speaker:hustle. Insoluble fiber is the plumbing that you
Speaker:need. So I want you to realize that fiber just
Speaker:keeps things moving forward. All right, I'll see
Speaker:myself out.
Speaker:>> Dr. Terry Simpson: Yeah. If you honestly believe he's through, you're
Speaker:fooling yourself or haven't listened to these long
Speaker:enough. Okay, let's go, doc.
Speaker:>> Dr. Terry Simpson: Here's the other part that gives some people
Speaker:trouble. It's called fermentable fiber. This is
Speaker:things like beans, onions, garlic, asparagus,
Speaker:resistant starches. This is the fiber that feeds
Speaker:your gut bacteria. And when you feed the so called
Speaker:good bacteria, the part of your microbiome that
Speaker:you want, those microbiome tend to grow better and
Speaker:they will crowd out, uh, those bacteria that don't
Speaker:like fiber as much. And those good bacteria, they
Speaker:produce short chain fatty acids. This isn't fat.
Speaker:These are short chain fatty acids that your body
Speaker:uses for basic building blocks. And the most
Speaker:important one they make is butyrate. Which brings
Speaker:me to one of my favorite Internet myths. I've had
Speaker:carnivore people tell me very confidently that
Speaker:butyrate comes from butter. That butter is called
Speaker:butter because it contains butyrate. No, butter is
Speaker:called butter because the word comes from the
Speaker:Latin and the Greek, meaning cow cheese. Now,
Speaker:butyric acid was named because it was first
Speaker:isolated from a rancid butter, but not because
Speaker:butter is a good way to get it. The butyrate that
Speaker:matters is made in your colon by bacteria from
Speaker:fermentable fiber. Dietary butyrate from butter is
Speaker:absorbed in the small intestine and disappears. I
Speaker:mean, if butter were good colon therapy,
Speaker:gastroenterologists would prescribe croissants.
Speaker:And sadly, they do not. I mean, if croissants
Speaker:fixed your gut, Paris would be the healthiest city
Speaker:on, on earth. Now, let's talk about fiber
Speaker:supplements. And there are a lot of them out
Speaker:There. Benefiber, psyllium, husk, metamucil,
Speaker:citrusyl, others. And most of them will give you 4
Speaker:to 5 grams of fiber. That's about 10% of what you
Speaker:should get in a day. Helpful? Yes. Enough, No. I
Speaker:personally like a fiber supplement called Loam L O
Speaker:A M M which gives you about 12 grams of mixed
Speaker:fiber. And I use it in my morning smoothie. Now
Speaker:that's a bridge. It's not a replacement. But if
Speaker:your entire fiber strategy fits in a scoop, you're
Speaker:missing the point. Let's talk about irritable
Speaker:bowel syndrome or ibs. These people are the ones
Speaker:that'll say fiber makes them feel worse. Sometimes
Speaker:at first they're right. Because fermentable fiber
Speaker:produces gas and IBS guts are sensitive to gas.
Speaker:We're all sensitive to gas. Some clinicians use
Speaker:what's called the fodmap diet as a temporary
Speaker:elimination tool to identify the triggers. But we
Speaker:don't live there. We use a Mediterranean style
Speaker:diet, which in recent series has been shown more
Speaker:important to identify problems and reintroduce
Speaker:foods. Now, I've heard some of the paleo ancestral
Speaker:diet people say, oh, use the whole 30. It's an
Speaker:elimination diet. It's not. It's low carb cosplay.
Speaker:We eliminate to learn, not to live. Afraid of
Speaker:food. Now people ask, what does eating enough
Speaker:fiber actually look like? Because you want to do
Speaker:this without thinking about it. And if you want, I
Speaker:have a three day Mediterranean diet that's free on
Speaker:terrysimpson.com but let me walk you through a
Speaker:simple day. In my morning, I have oats, berries, a
Speaker:little bit of nuts, maybe some chia seeds. In my
Speaker:smoothie that's a combination of soluble and
Speaker:insoluble fibers and some polyphenols. For lunch,
Speaker:I'll have some vegetables, carrots, some beans or
Speaker:lentils. I'll have some whole grains, like maybe
Speaker:a, uh, sandwich. And this is where the microbiome
Speaker:starts smiling. For snack, I'll have a stone
Speaker:fruit, maybe some nuts. I don't have a protein
Speaker:bar. Most of those kind of have the texture of
Speaker:drywall and the taste close to what I would
Speaker:imagine drywall would taste like. And dinner is
Speaker:pretty simple. I have some vegetables and I have
Speaker:whole grains like farro and some fish or poultry.
Speaker:Now, this kind of eating routinely delivers about
Speaker:25 to 40 grams of fiber. No spreadsheets, no apps,
Speaker:no drama. And with my loam, I'm getting in at
Speaker:least 37 to 50 grams of fiber easily. So if you're
Speaker:part of that 92%. And if you're listening to this,
Speaker:you probably are that are not getting enough
Speaker:fiber. Go slow, increase gradually. Make sure
Speaker:you're well hydrated. Remember my desk. And
Speaker:remember this. You're not fragile, but you might
Speaker:be flammable. Now, fiber isn't magic. It's not
Speaker:trendy. It doesn't have any influencers. It needs
Speaker:forks. And if you're bringing your phone into the
Speaker:bathroom just in case, that's not aging, that's
Speaker:fiber deficiency. Please see the blog associated
Speaker:with this@yourdoctorsorders.com and and check out
Speaker:my substack@drsimpson.com the podcast was
Speaker:researched and written by me, Dr. Terry Simpson.
Speaker:And while I am a board certified physician, I am
Speaker:not your physician. And before making any changes
Speaker:to your diet, please talk with your board
Speaker:certified physician and a registered dietitian.
Speaker:Don't talk to a chiropractor or some functional
Speaker:medicine witch doctor guru. All things audio are
Speaker:done by my friends at Simpler media. And the pod
Speaker:got himself Mr. Evo 2 Tara. And producer girl
Speaker:Productions is responsible for making me more
Speaker:interesting than I am. Have a good week,
Speaker:everybody. Hey, Evo, what's your favorite fiber?
Speaker:And keep candles away from the oats, buddy.
Speaker:>> Dr. Terry Simpson: Yeah, I'm pretty sure the problem was really more
Speaker:about the methane, uh, than the oats themselves.
