Soluble vs Insoluble Fiber Explained in 7 Minutes

You’ve heard “eat more fiber,” but almost nobody explains it in a way clients actually remember or apply. We keep it simple and useful: soluble fiber acts like a sponge, and insoluble fiber works like a broom. That one shift makes nutrition coaching easier, whether you’re helping a client manage hunger, improve gut health, or make sense of cholesterol labs without getting lost in jargon.

We walk through what soluble fiber does best, including slowing digestion, blunting blood sugar spikes, and supporting healthier LDL cholesterol levels. Then we connect it to real foods people will eat: oats, apples (yes, the skin counts), berries, beans, carrots, flax, and chia. From there, we cover insoluble fiber and why it matters for fullness and regularity, with practical examples like whole wheat, brown rice, seeds, and leafy greens. We also talk about how most foods are a blend, so you don’t need a perfect list, you need a consistent pattern.

If you’ve been hearing loud takes about fruit being “bad” because of fructose, we address that fear head-on and explain why fiber-rich fruit can be a net positive for heart health and digestion. We finish with coaching strategy: fiber targets (roughly 38g for men and 25g for women), why jumping from low fiber to high fiber overnight backfires, and how to progress it like training. Subscribe, share this with a trainer friend, and leave a rating and review if it helps you coach nutrition with more confidence.

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Transcript

Welcome And Quick Calls To Action

SPEAKER_00 0:00

Welcome to the Show Up Fitness podcast where great personal trainers are made. We are changing the fitness industry one qualified trainer at a time with our in-person and online personal training certification. If you want to become an elite personal trainer, head on over to showufffitness.com. Also make sure to check out my book, How to Become a Successful Personal Trainer. Don't forget to subscribe, rate, and review. Have a great day and keep showing up.

Soluble Fiber As A Sponge

SPEAKER_00 0:27

So one of the questions that Marcus asked was the difference between soluble and insoluble. And again, there's a call where Jay has a whole hour, the our team RD, and she goes over it. But here's a little breakdown, like your Cliff Notes. And you can use like the S part of soluble for its slows or it's a sponge. It's going to soak up. So this is type of fiber that is going to soak up in your blood. It's going to decrease your LDLs. It's a sponge. So it's going to attach to that stuff and get it out of your system, go back to the liver, and the liver is going to do a bunch of cool stuff. And that's why cholesterol is so important because when we get it out of the system, that's going to actually lower ultimately our total cholesterol, specifically the low density ones. And those are what we classify as the bad ones. But as we know, which we'll take a look at here in a second with vitality, we need to take a deeper look into it and not just simple LDLs. When you are above 100, that's considered a risk factor. When you're greater than 130, that's uh significantly against you in the sense that your arteries could be building up with plaque. It's gonna slow down your sugar spikes or blunt sugar spikes. Great for gut health because of the sponge effect. Things that you're gonna see will be oats and apples, specifically the skin on the apple, berries, beans, carrots, flax, chia seeds, those are all examples of soluble. Notice

Insoluble Fiber And Bathroom Truths

SPEAKER_00 1:50

how I have both right here. It's not just black and white, like a bench press is primarily just for your chest and that's it. And uh squat is for your glutes per se. It's not like that with soluble and insoluble. You're gonna get a combination of both. Carrot may have more soluble, but there would be insoluble factors. When you think of insoluble, think of the stuff you're gonna see in the toilet. Now, if you eat a bunch of corn, you're gonna see the casing of the corn and your poo-poo. The proper term for that would be your fecal matter when you defecate, but that's the stuff you're gonna see in the toilet. It adds bulk, it decreases constipation, so it just makes you feel fuller. And some of those foods would be your whole wheats, brown rice, seeds, leafy greens. And then they give an example that I think is really good with how it's a combination of both, with a ripe banana, the green one, being more soluble, but as it turns more yellow, it's gonna be better more for your gut health, and it's gonna be more insoluble. Increase slows down. This is gonna think of it as um a broom and a sponge. So I like those little examples right there, and hopefully it helps. Yes, it would be more on the insoluble side. They do have some soluble characteristics like that. Pear, for example, the coating of the pear would be a soluble aspect, but the the other nutrients within there. And with fiber, it's again, it's one component because you could take a look at berries, for example. And blackberries have significantly more fiber because of the cell walls. But right now, be careful because your your gut health could be screwed up if you're getting some of those parasites, and those parasites are gonna live inside of the raspberries and blackberries in those crevices because we can't get the parasites out. So without the the fear of today and what we're living with, but uh in the perfect world, when you look at a berry, a blackberry has more fiber, a blueberry is gonna have significantly less, but we're not saying blackberries are better than blueberries. That's why you'd have a fruit cocktail and you have blackberries, blueberries, watermelon, melon, banana, you're getting a combination of both. I think it's it's good to look at fiber in the same way as like protein. And we're not just saying have pork all the time. Lean pork is the way to go, or fish is the way to go. Obviously, if you're a pescatarian, it's different, but it's you know, get a variety.

Variety Strategy And Daily Fiber Targets

SPEAKER_00 4:12

So if you're from for the client's perspective, I think you can approach this in two different ways. One, suggest a different fruit per day. This is where you can use your social media to get in your story, eat an apple if you want to be funny or try to be funny like I do. It's like you can be chomping on the apple and say, what's the most annoying thing in the world? Someone eating an apple or someone who's talking about peptides. And you know, apple benefits here. Next day it's a pear. Do the same thing, here are the benefits. Next day, blackberry, next day, banana, next day, uh chia seeds, whatever it is. Because dudes should be getting close to 40 grams, females should be getting close to 30 grams. They say 38 for males, 25 for ladies. And I think just like with protein and just like with exercise in general, we're not even close to the bare minimum.

Ramp Fiber Up Without Gut Chaos

SPEAKER_00 4:57

So, with that being said, there are some great questions that Jay answered that people were asking about that ramp up. Because if you take someone who is primarily consuming processed foods and you switch them over into whole foods, and now every single day they're getting three apples and a bunch of blackberries, awareness of their digestion is probably going to increase in the sense that they're gonna feel fuller, they're gonna have more bulk, and they're gonna defecate more. So going from five grams all the way up to 40 grams may be a little aggressive, and keep that in mind with the supplementation. We're not saying go out there and take 10 servings of metamusle. So, you know, looking at your client's daily intake, get the week calculation, all things that we talk about within the phases, metabolic awareness, behavioral augmentation, the second phase, and then moving into longevity integration. If you have a client and you look at their total caloric consumption for the week on average, it's three 3,000 calories, 10 grams of fiber, and 50 grams of protein. Have a plan for them to slowly increase. You could have a PDF printout, choose two of these, and you have some that are soluble, some that are insoluble, knowing that they're both beneficial for heart health. And this is the one that's gonna help decrease chances of corneal artery disease. And it's just not a sexy topic today. I think it's getting more popular, which is good, more awareness, but we're still kind of battling with the whole, you know, the sugar spikes that we're freaking out about and the irony behind that, right? Where you hear the carnivore folks saying, don't have any type of fruit, it's bad for you because of you know, fructose. Well, in actuality, soluble fiber, which these are fruit, apples, berries, and so forth, they will have a positive impact on your health.

Coach It Like Training Progressions

SPEAKER_00 6:45

Any other questions on soluble versus insoluble before we get into a report from Mr. Cody? How you would respond, let's put this into a weightlifting perspective, Marcus. It's a it's a newbie. They've never worked out, and it's day one, and you assess them and they say, hey, you know, can we start incorporating some conjugate? You know, I want to start, you know, doing some daily undulating periodization and you know, supersets and tricep, and compound sets, and drop sets. Just like hold your horses, tiger. We haven't worked out since COVID. Let's just get through today. The most important workout you can do is the next one.