Wil Bulsiewicz: Why Fiber Is the One Nutrient That Reduces Your Risk of Every Major Disease

Added: 2026-05-30

[00:00:00]Let's go into fiber, because I feel like whenever I think of fiber now, I think of you. Um, which I hope that you're happy about, because you know >> Oh, I'm very happy about that. That's a dream come true.

[00:00:09]>> [laughter] [gasps] >> You know, like we'll be as like the fiber, the fiber guru. And you talk about nutrition workhorses in your book, like the four nutrition workhorses. And people always love things that they have structure to, right? Um, and fiber is the first part of that. Now, fiber is a word that has been spoken about a lot than the protein kind of phase has come in. And again, it's it's an important macronutrient, but I don't think they should be going against one another. I think we need to talk about these, you know, together. They all constitute a healthy diet, healthy plate. But when people like thinking about fiber, they're saying that I have realized within my clinic and within the show, and people that write in, and you know, people the favorite part of this whole podcast is got the gut microbiome. Whenever we do an episode on the gut microbiome, our listeners absolutely love it. As you know. And um, fiber, it's an interesting one, because there's different forms of fiber. Um, and then some people will write in the comment section. I looked at our last few videos that had, you know, such a a high engagement. And people are like, but I'm adding in all this fiber, and I'm still in pain. You know, like what's going on? Um, so I thought like, should we just dissect fiber a little bit for to get people to understand it, like, you know, what does it really look like?

[00:01:23]What types of fiber should they be eating? And if they are eating a lot of fiber, but still having pain, what do you suggest?

[00:01:30]>> Fiber is to me the longevity nutrient.

[00:01:36]If you it's been shown more than any other nutrient to reduce your risk of disease, including the most dangerous diseases that exist.

[00:01:45]Heart disease, cancer, stroke, diabetes, Alzheimer's, chronic kidney disease.

[00:01:50]I can point you to the studies for fiber.

[00:01:54]So, the those studies don't exist with increasing your protein.

[00:01:59]I do think protein is important, but it shouldn't come at the expense of our fiber.

[00:02:04]And we have a fiber problem. We don't have a protein problem. We have a fiber problem.

[00:02:08]And so, addressing this becomes, I think, quite essential. And these four nutrition workhorses that I describe in my book, the way that I landed on these four were that I basically said, "Okay, I want to know like what are the foundations of an anti-inflammatory diet?

[00:02:28]It needs to be important and powerful, and it needs to be missing for the vast majority of people.

[00:02:35]Because those are the greatest opportunities that exist for our health from a nutrition perspective. If you can take the thing that's missing and also powerful and actually address that, that's how you radically transform your health. Fiber is one of them.

[00:02:49]So, the thing about fiber is, first of all, all plant-based foods have fiber.

[00:02:53]Every single plant-based food has fiber.

[00:02:54]Fruits, vegetables, whole grains, seeds, nuts, legumes, mushrooms are technically not plants.

[00:03:00]>> [snorts] >> Fungi.

[00:03:01]>> They're fungi.

[00:03:03]But I am I am going to bestow upon mushrooms, they are honorary plants, because they have fiber and they also have polyphenols. So, that's kind of cool.

[00:03:13]So, and fiber is a nutrient that is kind of like protein. Uh so, protein, you would never say that the protein in fish is the same as the protein in beef or in a bean.

[00:03:23]They're unique. Different plants have different types of protein di- different types of fiber. They have different types of protein, too, but >> [laughter] >> That is technically correct as well.

[00:03:31]>> It is an important point, actually, that often gets lost is plants have protein, too. But the only place that you're going to find fiber is actually in these plant-based foods, and each has unique forms of fiber. We tend to break it into like two main categories, soluble and insoluble.

[00:03:47]Insoluble is the grit. Insoluble is the type that doesn't get digested at all.

[00:03:52]It's the kinds that ultimately you're going to poop it out.

[00:03:56]Whereas soluble fiber is the kind that you and I have been talking about where I said like fiber feeds the right colon, fiber feeds the microbes, fiber becomes short-chain fatty acids. That's soluble fiber.

[00:04:08]You don't need to worry too much about like what contains what in terms of these plant foods. You just need to eat a variety.

[00:04:15]Because when you eat a variety of foods, they variety of plant-based foods, they all have fiber, they all have different types, they all have a blend of soluble and insoluble, and ultimately that diversity is going to create harmony and balance within your gut. And that's exactly what you want.

[00:04:30]Now some people they struggle to add fiber. Why would that be?

[00:04:35]If it's so good, Dr. B, why is it hard?

[00:04:38]And it's like exercise.

[00:04:41]Is exercise good? Yes, of course it is.

[00:04:44]We 100% agree that exercise is good.

[00:04:48]Is there such a thing as too much exercise for a person? Yes.

[00:04:54]Is exercise hard, especially to get started in the beginning, but eventually it becomes addictive? Yes.

[00:05:00]If you haven't been exercising, the first couple weeks are challenging.

[00:05:05]So how do we exercise?

[00:05:07]We match our capabilities to the work that we do.

[00:05:14]So whatever it is that your body is capable of, and we have different muscle groups, and certain muscle groups might be stronger than others, but you eventually, if you go to the gym enough, you start to figure out, "Hey, this is what I'm able to do with when I do a curl, when I do a tricep extension, when I do a bench press."

[00:05:30]And you have that number.

[00:05:32]And then you start to work on that number, and it starts to slowly increase over time because you're getting stronger. Your body is adapting.

[00:05:39]You have You are teaching your body what you want to do, which is to become more proficient at doing these particular exercises.

[00:05:46]The same is true with fiber. All of that is the way that this works. This is exactly the way that it works.

[00:05:51]Fiber is exercise for your gut.

[00:05:54]You should match your fiber intake to what your gut is capable of.

[00:05:57]Chances are for most people, you haven't really been consuming fiber.

[00:06:01]So, that's kind of like starting from scratch at the gym. So, when you go to the gym, you start really low. When you start adding fiber, you start really low.

[00:06:08]And then you slowly introduce it because your gut starts to adapt to it in the same way that we were talking about with the 15-day study. Your microbiome becomes adapted.

[00:06:16]It becomes more efficient. It becomes more capable. It will start producing even more short-chain fatty acids from the same amount.

[00:06:23]But just like exercise, you can start to ratchet up.

[00:06:27]So, you know, if you want to like give a specific number to it, I would say something along the lines of like adding 3 g of fiber per week.

[00:06:35]>> What does that look like in terms of food? Like trying to understand 3 g for many people.

[00:06:40]>> So, like an extra 3 g of fiber and when I say 3 g, by the way, this is on a kind of daily basis, right? So, like so, most of us are starting around 15-ish, 15-ish grams.

[00:06:52]So, you add an extra three. If you try to double that, that's like trying to go to the gym and lift the heaviest weights in the gym all at once.

[00:06:59]Right?

[00:07:00]>> You're going to get injured.

[00:07:02]>> You're going to get hurt. Yeah, that's not a good idea.

[00:07:06]You add 3 g, that could be like uh an apple.

[00:07:10]Right? Eating an eating an extra apple once a day. Could be a handful of nuts.

[00:07:15]When it comes to beans, it's actually not that many beans. Beans are so densely packed with fiber. That's the reason why a lot of people struggle with beans.

[00:07:21]Because they're so packed that like you just get the four-bean chili and next thing you know, it's like you've overwhelmed your system.