NOW READING:Fiber: The Nutrient Most of Us Aren’t Getting Enough Of

September 04, 2026

Fiber: The Nutrient Most of Us Aren’t Getting Enough Of

Protein gets a lot of attention. Fiber deserves a whole lot more.

Fiber plays a role in digestive health, blood sugar regulation, cholesterol, satiety, the gut microbiome, and long-term cardiovascular and metabolic health. Yet it remains one of the nutrients Americans consistently fail to get enough of.

And unlike protein, which is abundant across many different types of foods, naturally occurring dietary fiber is found in plant foods: beans, lentils, whole grains, vegetables, fruits, nuts and seeds.

That is one of the reasons fiber matters so much to us at Plant Strong.

When you build meals around whole plant foods, you aren't simply removing something from the plate. You're adding something extraordinarily important back in.

America Has a Fiber Problem

The general benchmark for fiber intake is approximately 14 grams for every 1,000 calories consumed. Depending on age and sex, that translates to roughly 22 to 34 grams per day for most adults.

But we're not getting close.

Recent federal dietary data found that American men ages 19 and older consume an average of only 18.1 grams of fiber per day, while women average just 15.1 grams. Only about 4% of adult men and 11% of adult women consumed amounts above the Adequate Intake.

Earlier Dietary Guidelines data told essentially the same story: more than 90% of women and 97% of men failed to meet recommended fiber intake.

Think about that for a moment.

We spend enormous amounts of time debating carbohydrates, protein and fat, while one of the clearest nutritional shortcomings in the American diet receives comparatively little attention.

At Plant Strong, we think fiber deserves a promotion.

What Exactly Is Fiber?

Dietary fiber is a type of carbohydrate that our digestive enzymes cannot fully break down and absorb in the small intestine.

But "fiber" isn't one single substance.

Plant foods contain many different fibers with different structures and different effects in the body. Traditionally, fiber has been divided into two familiar categories: soluble and insoluble.

That's a helpful starting point, although modern fiber science goes further. Researchers increasingly consider characteristics such as a fiber's viscosity, fermentability and ability to hold water, because these properties help determine what a particular fiber actually does inside the body.

In other words, the best strategy isn't to hunt for one magical type of fiber.

It's to eat a diversity of whole plant foods.

Soluble Fiber: The Gel Former

Soluble fiber interacts with water and, depending on the type, can form a gel-like substance in the digestive tract.

You'll find soluble fibers in foods including:

oats and barley
beans and lentils
apples and citrus
carrots and other vegetables
flax and other seeds

Certain viscous soluble fibers can slow the absorption of nutrients, helping moderate the rise in blood sugar following a meal. Some also interfere with bile-acid reabsorption, one of the mechanisms through which soluble fiber can help reduce LDL cholesterol.

Oats and barley are particularly interesting because they contain beta-glucan, a viscous soluble fiber studied extensively for its effects on LDL cholesterol, post-meal blood glucose and the gut microbiota.

This is one reason we're so fond of starting the morning with a bowl built around whole oats.

Insoluble Fiber: The Bulk Builder

Insoluble fiber doesn't dissolve in water in the same way.

It includes fibers such as cellulose, some hemicelluloses and lignin and is abundant in foods including:

whole grains
wheat bran
vegetables
nuts and seeds
fruit and vegetable skins

Some insoluble fibers help increase stool bulk and support normal movement through the digestive tract. Research also suggests that insoluble fibers interact with the gut microbiome and may contribute to intestinal barrier function and overall gut homeostasis.

It's the part of fiber's résumé most people already know:

Fiber keeps things moving.

But that's only the beginning.

Fermentable Fiber: Dinner for Your Microbes

Some fibers make it all the way to the large intestine, where they become food for microbes living in the gut.

This is where fiber gets particularly fascinating.

Gut bacteria can ferment certain fibers and produce compounds called short-chain fatty acids, including acetate, propionate and butyrate.

These metabolites are involved in maintaining the intestinal environment and may influence immune function, metabolic signaling, insulin sensitivity and lipid metabolism. Research into this relationship between fiber and the microbiome continues to evolve rapidly.

You may also hear some fermentable fibers described as prebiotic fibers because they provide substrates that beneficial gut microbes can use.

This is an important distinction:

Probiotics are microbes. Prebiotics help feed them.

Beans, lentils, whole grains, vegetables, fruits, nuts and seeds deliver numerous fermentable carbohydrates and fibers within a much larger package of naturally occurring nutrients and phytochemicals.

That diversity matters.

Fiber and Your Heart

Fiber is not merely a digestive-health nutrient.

Higher fiber intake has repeatedly been associated with better cardiovascular health.

Research links dietary fiber with improvements in several cardiovascular risk factors, including LDL cholesterol, blood glucose regulation and weight management. Large observational analyses also consistently associate higher fiber consumption with lower risk of coronary heart disease, stroke and cardiovascular mortality.

Different fibers may contribute through different pathways.

Viscous soluble fiber can influence cholesterol metabolism. Fermentable fiber interacts with the microbiome. High-fiber foods also tend to displace highly refined foods while providing potassium, magnesium, phytochemicals and other compounds associated with better cardiometabolic health.

This is where focusing solely on individual nutrients can miss the bigger picture.

A bean isn't just fiber.

An oat isn't just beta-glucan.

A berry isn't just antioxidants.

Whole plant foods deliver these components together.

Fiber and Blood Sugar

There's a strange tendency to talk about all carbohydrates as though they're interchangeable.

They aren't.

Compare drinking a refined sugary beverage with eating a bowl of oats, berries, flaxseed and walnuts. Both contain carbohydrate. Their structure, fiber content, nutrient density, rate of digestion and physiological effects are dramatically different.

Fiber isn't broken down and absorbed as glucose in the same way digestible carbohydrates are. Viscous soluble fiber can also slow digestion and nutrient absorption, helping blunt the post-meal rise in blood glucose.

This is why we prefer to talk about food, rather than simply labeling an entire macronutrient category "good" or "bad."

Beans are carbohydrates.

Oats are carbohydrates.

Apples are carbohydrates.

And they come wrapped in fiber.

Fiber Helps Make Food Satisfying

High-fiber foods tend to require more chewing, occupy more volume and move through the digestive system differently than highly refined foods.

That helps explain why fiber-rich meals can be so satisfying.

It's also why our goal isn't simply to manufacture the fewest-calorie food possible.

We want to help people build meals around real food that actually feeds them.

Whole grains. Beans. Lentils. Vegetables. Fruits. Nuts. Seeds.

These are foods that bring fiber along for the ride.

Why Fiber Matters So Much at Plant Strong

Fiber isn't something we sprinkle into a product so we can make a marketing claim.

Our philosophy starts with the foods that naturally contain it.

Plant Strong foods are built around ingredients such as whole grains, beans, lentils, vegetables, nuts and seeds. Our current product philosophy specifically calls out naturally occurring fiber from whole ingredients as one of the characteristics we value because of its contribution to digestion, fullness and everyday gut health.

Take our chilis.

Beans and lentils aren't simply convenient sources of plant protein. They're also naturally rich in fiber.

Our current Creamy White Bean Chili provides 7 grams of fiber per serving, while Chunky Chipotle Chili provides 8 grams per serving.

Or look at breakfast.

Rip's Big Bowl begins with foods like rolled oats and whole wheat rather than refined grains stripped of much of their natural structure.

And then we encourage you to build from there.

Add berries.

Add banana.

Add ground flax.

Add chia.

Add walnuts.

Suddenly breakfast isn't simply cereal. It becomes a bowl full of different plants delivering different fibers.

That's the Plant Strong idea in action.

Start with a strong foundation. Then pile on the plants.

Food First: Why the Source of Fiber Matters

You can now buy bars, powders, drinks and processed foods fortified with isolated fibers.

Some functional fibers absolutely have demonstrated health benefits, and certain supplemental fibers can be useful clinically. But different isolated fibers behave differently in the body, so seeing "10 grams of fiber" on a package doesn't necessarily tell you everything about how that food will affect you.

Whole plant foods offer something fiber powder cannot replicate easily: a complex mixture of different fibers alongside vitamins, minerals, phytochemicals and intact food structures.

So rather than beginning with:

How can I add a fiber supplement?

We'd rather begin with:

How many whole plant foods can I get onto my plate today?

An Easy Way to Get More Fiber

You don't have to calculate every gram.

Simply start adding plants throughout the day.

At breakfast:
Choose oats or other whole grains. Add berries, bananas, flaxseed, chia or nuts.

At lunch:
Build around beans, lentils or whole grains. Add greens and another vegetable or two.

At dinner:
Start with beans, lentils, potatoes, sweet potatoes or intact grains and pile on vegetables.

For snacks:
Reach for whole fruit, vegetables, nuts or seeds.

And here's one of our favorite strategies:

Add instead of obsessing over subtraction.

Add beans.

Add greens.

Add berries.

Add oats.

Add another vegetable.

Add a tablespoon of ground flax.

The more whole plants you add, the easier it becomes for fiber to accumulate naturally.

If you're dramatically increasing your fiber intake, increase it progressively and drink adequate fluids; a sudden jump can cause temporary gas, bloating or digestive discomfort while your system adjusts.

Don't Just Count Plants. Diversify Them.

One final point is worth emphasizing.

Soluble versus insoluble is useful shorthand, but fiber science increasingly suggests that diversity matters.

Different plants contain different combinations of fibers. Those fibers differ in viscosity, fermentability and structure, and different gut microbes may use them differently.

That gives us another reason to eat broadly across the plant kingdom.

Oats today.

Beans at lunch.

Lentils tomorrow.

Berries, apples, greens, broccoli, potatoes, brown rice, barley, flax, chia.

Your gut doesn't need one superfood.

It benefits from a team.

The Bottom Line

Most Americans aren't suffering from a fiber shortage because fiber is difficult to find.

We're falling short because the modern food environment is dominated by foods that have been refined, processed and stripped of much of the fiber-rich plant material humans traditionally consumed.

The solution can be surprisingly simple:

Put plants back at the center of the plate.

Whole grains. Beans. Lentils. Vegetables. Fruit. Nuts. Seeds.

At Plant Strong, we care about fiber because we care about the foods that contain it.

And when your meals begin with those foods, getting more fiber isn't another nutritional chore to add to your list.

It becomes a natural consequence of eating Plant Strong.