Fiber’s Big Glow-Up

I’ve spent my life bored by fiber, thinking it was only good for bowel regularity, or, at best, a grandparent conversation-starter. But when I scroll through recipes on social media these days, the videos showing up on my feed are a different and, dare I say, exciting side of this essential nutrient. One creator smashes magenta raspberries into a jammy layer for chia pudding. Another tosses sun-soaked orange sweet potatoes and vibrant green kale into a polychromatic salad. Feeling inspired, I save a few recipes and add their ingredients to my grocery list.  

And one thing all of those extremely colorful ingredients have in common? Fiber. Who would’ve thought this nutrient was the unsung hero of the nutrition world? 

High fiber intake is linked to reduced risk of type 2 diabetes, cardiovascular disease and colorectal cancer, as well as to a nearly 23% lower risk of dying from any cause. What drug, especially one that’s budget-friendly, widely available and essentially free of side effects, can say the same?

While we may have spent the last couple of years fixated on protein, lately TikTok has been buzzing with “fibermaxxing.” This trend has people boosting their daily fiber intake to meet or exceed the recommended levels—eating as much as 50 grams, nearly twice the daily recommended amount (please don’t try this). Food companies are creating new or enhanced products with added fiber, like sports drinks, chips and prebiotic sodas. A 2026 report from market research group Datassential predicted that “fiber is set to be the next big health trend,” noting that more than half of U.S. consumers are curious about fibermaxxing once they learn what it is.

“The nutrient of the year is fiber,” agrees Andrew Reynolds, Ph.D., M.P.H., an epidemiologist at the University of Otago in New Zealand who studies dietary fiber. 

So, what’s changed? How did fiber go from boring old constipation-preventer to superstar of 2026? Is it social media, our growing interest in gut health or something new in the research?

As I dip my spoon into a pot of that magenta jam-swirled creamy chia pudding (could be breakfast, could be dessert!), I’m really not thinking about any of this—about mortality statistics or market trends. I’m licking my spoon and tasting a whole lot of joy that just happens to be packed with fiber.

What Does Fiber Actually Do in the Body?

On paper, fiber sounds unimpressive. It’s not a vitamin that helps fuel cells or a mineral that transports oxygen. It’s the indigestible portion of plant foods; material our bodies can’t break down or absorb. 

So how can something we don’t even digest wield so much power? 

Teresa Fung, RD, Sc.D., lights up when I ask. A nutritional epidemiologist, conducting research at the Harvard T.H. Chan School of Public Health and teaching at Simmons University in Boston, she was part of the 2025 Dietary Guidelines Advisory Committee, the group that assembled evidence for the U.S. fiber guidelines. Fung explains that fiber’s refusal to be digested is exactly where its strength lies. 

When we eat plants, she says, many different types of fibers, including cellulose, lignin, resistant starch and beta-glucan, enter the digestive tract. The highest concentrations are found in the bran and germ of cereal grains, in the skins of fruits and vegetables and in legumes, though fiber exists throughout plant tissues.

Fiber’s refusal to be digested is exactly where its strength lies. 

While many people still use the terms “soluble” and “insoluble,” Fung says experts increasingly categorize fiber as viscous, meaning gel-forming, or nonviscous. In the small intestine, viscous fibers absorb water and form a thick gel that moves slowly, almost like honey. “Viscous fiber, because it holds water … it makes the material soft,” she explains. “It prevents constipation.”

That gel does more than keep things moving. Viscous fibers, such as beta-glucan, bind cholesterol in the small intestine, helping lower levels of circulating LDL cholesterol (known as “bad” cholesterol). They also slow the absorption of sugar, preventing sharp blood sugar spikes and reducing the risk of type 2 diabetes.

Take an apple, for instance. Its fiber creates a natural scaffold around the fruit’s sugars, so your body has to work through that structure before accessing the sugar. The result is a steadier release into the bloodstream. Compare this to apple juice, where the fiber is gone and the sugar hits fast. 

“So instead of having a quick spike in your blood sugars, which your body then has to respond to, fiber actually slows down that spike,” says Reynolds.

In the large intestine, fiber continues its work. Some types help speed waste through the colon, reducing the time potential toxins, such as cadmium and lead, linger. And Reynolds notes that certain types of fiber are abrasive and can scrape off cells from the colon's walls as they move through, which may help promote turnover of those cells. Researchers suspect this could be one reason that higher fiber intake is linked to lower colorectal cancer risk.

The interesting thing, Fung says, is that we define fiber primarily by its relationship to us: “When humans cannot digest parts of the plants, that’s fiber.” Our inability to digest fiber is fiber’s gift.

Fiber Feeds the Gut Microbiome

Once the fiber moves through the small intestine into the large intestine, a second round of nutritional magic happens. “We are the hosts of a massive organization called the gut microbiome, and the microbes that live in that organization have the ability to digest fiber,” says Reynolds.

Fermentable fibers act as prebiotics, meaning they feed beneficial bacteria. As Fung puts it, “We’ve got to feed those bacteria. It’s like having a pet.”

When microbes break down these fibers, they produce short-chain fatty acids (SCFAs) such as acetate, butyrate and propionate. These compounds help maintain the integrity of the intestinal lining and may reduce chronic inflammation, a process linked to conditions such as heart disease and type 2 diabetes. Some research suggests SCFAs may also improve insulin sensitivity, which refers to how effectively your body responds to insulin and moves sugar from your bloodstream into your cells. When insulin sensitivity is higher, blood sugar levels are easier to regulate.

Reynolds describes what happens to the microbiome if fiber intake is chronically low. “It’s not a diverse microbiome, it’s not a dense microbiome, and it’s not a functional microbiome in that it’s not producing a lot of those short-chain fatty acids.” 

The encouraging news is that increasing fiber intake can help restore gut diversity and function. Some research suggests that SCFAs may also stimulate the release of GLP-1, a hormone that plays a role in satiety, similar to GLP-1 agonist drugs like Ozempic and Wegovy.

Even more intriguing, early-stage research is exploring how these fatty acids may influence communication between the gut and the brain. Scientists are studying what’s known as the microbiota-gut-brain axis to better understand how fiber, gut bacteria and their byproducts might affect cognitive function and mental health. One review, for example, notes that fiber supports the growth of beneficial bacteria associated with improved cognitive function, such as Bifidobacterium and Lactobacillus strains.

Fiber is the Ultimate Nutritional Multi-Tasker

With its diverse ways of interacting with the body, fiber greases many physiological wheels. Reynolds explains that fiber does everything “from blunting sugars, to reducing the amount of circulating cholesterol, to producing the benefits from the microbiome, as well as having effects on things like satiety and hunger.” He pauses. “It's quite a lot, isn’t it?”

Reynolds worked on the 2023 World Health Organization recommendation for fiber, which was largely based on a sweeping systematic review and meta-analysis he conducted in 2018. He and his colleagues analyzed 58 clinical trials and 185 prospective studies to examine the link between fiber intake and disease. The findings were striking. Higher fiber intake is associated with lower body weight, blood pressure, and total cholesterol, as well as a reduced risk of heart disease, stroke, colorectal cancer and type 2 diabetes.

And the research keeps building. Since that 2019 paper, new studies continue to underscore fiber’s broad reach. Eleanor Beck, Ph.D., a fiber researcher at the University of New South Wales in Sydney, Australia, recently published a review of 48 studies on cereal fibers, such as rye and oats, and their effects on appetite. With higher fiber intake, she says, “People said they felt a little bit more full for longer.” Less-processed foods such as rye porridge, rye kernels and rolled oats promote greater satiety than refined rye and oat flours.

Other recent research adds to the picture. A 2025 observational and genetic study found that people consuming more than 18 grams of fiber per day had a reduced risk of stroke. Another 2025 study found that fiber-rich, plant-forward diets were linked to fewer high-risk coronary plaques, while lower-fiber diets were associated with more unstable plaques that could rupture and lead to heart attacks. The potential benefits of fiber intake go beyond cardiovascular health too: A cross-sectional study of 30,000 people found that higher fiber intake, between 14 and 28 grams per day, was associated with a 27% lower risk of developing osteoarthritis compared to the lowest fiber intake.

And here’s the cherry on top. In 2024, researchers pooled data from 64 cohort studies following more than 3.5 million people over many years. Those consuming higher amounts of fiber had a 23% lower risk of death from any cause compared to those consuming the least. Higher fiber intake was also associated with a 26% lower risk of death from cardiovascular disease and a 22% lower risk of death from cancer.

Fiber Steps into the Spotlight

Taken together, the evidence helps explain why fiber is having a moment.

Gen Z is deeply interested in gut health. Colorectal cancer rates are rising among younger adults, and dietary patterns higher in fiber may play a protective role. Meanwhile, many people are taking GLP-1 medications such as Ozempic and Wegovy for diabetes and weight management. These drugs slow gastric emptying and can cause constipation and digestive discomfort, so health care providers commonly advise people taking them to prioritize fiber to support regularity, stabilize blood sugar and promote satiety. 

In other words, fiber is showing up exactly where modern health concerns are. Fiber may not be flashy. But in study after study, it keeps delivering. 

And that raises a practical question. If fiber is doing all of this behind the scenes, how much do we actually need to reap the benefits?

How Much Fiber Should We Eat?

The short answer: Probably more than you’re getting. It’s not just people on GLP-1 drugs who need to eat more fiber. When I asked scientists and dietitians how much fiber a typical person should eat, they invariably said, more.

According to Reynolds’ 2019 meta-analysis, eating 25 to 29 grams of fiber per day may reduce your risk of chronic disease and help you live a healthy life. The Nutrition Facts panel similarly advises consuming around 28 grams of fiber per day; the % DV you’ll see there is based on this number. Most American adults consume about half that. (Note that an individualized fiber intake recommendation depends on factors like age and sex.)

Hitting a daily target is one piece of the puzzle. Getting fiber from a variety of plant-based foods matters, too. “Foods contain a mix of different fibers,” says Reynolds. “So there’s not one fiber in whole grains and one fiber in vegetables. They have different ratios and different mixes.”

That diversity matters. Stefan Kabisch, M.D., a research physician at the Charité – Universitätsmedizin Berlin who studies fiber and inflammation, emphasizes variety. Kabisch explains that different bacteria feed on different types of fiber, so eating a wide range of plant foods helps support a broader, more resilient microbiome.

Whole foods remain the gold standard. They deliver fiber alongside vitamins, minerals and phytonutrients that work together in ways extracted fibers likely can’t replicate. However, fiber-enriched products and supplements may help fill gaps.

“If you can get it from foods, great,” says Reynolds. “But if you can’t achieve that amount with food, go to the supplement pathway.” Before beginning a supplement, check with your health care provider to ensure it meets your needs and won’t interact with any medications or other supplements you’re taking.

Welcoming Fiber into Our Kitchens

Back at my desk, munching on popcorn to boost my fiber intake, I scroll through recipe reels promising to help me increase it. I want to make all of them, but cooking fiber-rich meals three times a day feels daunting. 

So how do we increase our intake without overhauling our entire diet? 

Theresa Gentile, M.S., RDN, CDN, a Brooklyn-based dietitian and spokesperson for the Academy of Nutrition and Dietetics, suggests starting small. Think addition, not perfection, she says. 

Here’s how. 

1. Upgrade Your Plate. Gentile likes to add a fiber boost to the foods people are already eating. Start by adding at least one fruit or vegetable to every meal. “If you’re having a sandwich, try adding a handful of spinach or kale to it,” says Gentile. Or add some berries to your morning bowl of cereal.

2. Think 50-50. One of the easiest ways to boost fiber intake is to go half-and-half. “Typically, I swap half the meat in a recipe with legumes,” says Reynolds. Mix cooked black beans into your taco meat, or replace half of the chicken you’d typically add to a pot of soup with white beans. You can apply the same logic to grains, too. Try half-portions of whole-wheat and regular pasta or brown and white rice.

3. Make Snack Time Count. Aim to include a fiber-rich food in your snack. That could be as simple as an apple with peanut butter, a handful of nuts and dried fruit, yogurt topped with chia seeds or a bowl of popcorn. Even adding a sprinkle of our nutty, seedy High-Fiber Mix to something you’re already eating can quietly boost your daily total.

4. Eat a Variety of Plants. Different types of fiber do different things, says Fung, so variety is key. For example, start your morning with oats. They’re rich in beta-glucan, a viscous fiber linked to lower cholesterol and steadier blood sugar. At lunch and dinner, incorporate legumes like lentils or chickpeas and colorful vegetables (think bell peppers, leafy greens or sweet potatoes), which provide a mix of fibers that support digestion and feed beneficial gut bacteria.

As you bump up your fiber intake, experts suggest doing it slowly. It takes time for your gut to get used to more fiber, and suddenly doubling your intake can lead to bloating or an uncomfortable stomach. Also, make sure to drink plenty of water as you go—it will help reduce initial discomfort. This is because fiber works best when it has fluid to move with it.

People with certain gastrointestinal conditions, such as irritable bowel syndrome, may need to be more thoughtful about the types of fiber they eat. And, says Gentile, “If you’re taking certain supplements or medications, just make sure that if you have a sudden bump up in fiber, that you’re talking to your health care provider. Just to make sure it's not interfering with absorption.” 

Our Expert Take

Fibermaxxing may be a buzzy term, but the science behind it is solid: Eat more plant-based foods—from fruits and vegetables to whole grains, nuts and legumes. It’s guidance that most dietitians and scientists have promoted since the dawn of modern dietary advice. And it’s one of the best ways to support your long-term health.

“To get the battery of benefits, we really want lots of different fruits, lots of different vegetables, different beans and lentils and different types of whole grains,” says Fung. 

Fiber-rich foods are rarely dull. They’re crunchy, colorful and satisfying. When multiple fibers coexist in a dish, boredom doesn’t stand a chance. 

Now, when I open my fridge, five glass jars of summer sunshine beckon from the top shelf. I have gorgeous snacks to look forward to, pops of stunning color to decorate my desk. I’m going to stir a can of black beans into my family’s taco meat tonight. Easy—and yummy. And, they’re good for me. 

In a sea of extreme diets and quick fixes, eating more fiber is a trend wave I’m happy to ride.