What is “Fibermaxxing”?

This viral nutrition trend encourages eating more fiber — but most Americans are still falling short. Here’s what experts say about the benefits, risks, and the right way to do it.

If you’ve scrolled social media or wandered the online ecosystem in the past few weeks, you’ve probably encountered the newest food fad. Dubbed fibermaxxing, it’s the internet’s way of influencing health trends — and, for once, it might actually be good for you.

Fibermaxxing focuses on increasing a person’s daily fiber intake by boosting the consumption of vegetables, fruits, nuts, beans and whole grains. Unlike some other viral nutrition advice, this is a message experts support.

“I think it’s always a good thing when we can get people to increase their fiber intake,” says Eytan Stern, MS, RD, LD/N, CNSC, a research dietitian at the University of Miami Health System’s Crohn’s and Colitis Center. “I’m a big fan of introducing a fibrous or fiber containing food at every meal.”

Most of us, however, don’t consume enough fiber.

Adults need between 25 to 34 grams of fiber a day, depending on their age and sex, according to the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), which set the Dietary Guidelines for Americans every five years. (Children need 14 to 31 grams per day.)

Yet, a 2021 study concluded that only 7% of American adults actually meet those recommendations, with men at the low end (5%) and women doing slightly better (9%). 

The consequences can be serious. In addition to constipation and poor gut health, insufficient fiber intake has also been linked to a higher risk of diabetes and heart disease. Because of this worrisome gap between recommendation and reality, federal agencies have identified fiber as a “nutrient of concern” since 2005, hoping to emphasize the message that fiber has many benefits beyond digestive health.

What are the two types of dietary fiber?

Dietary fiber comes in two main types: soluble and insoluble—and both are important for your health.

• Soluble fiber dissolves in water and forms a gel-like substance that slows digestion. This helps support blood sugar control, heart health, and a balanced gut microbiome. Common sources include oats, apples, chia seeds, and psyllium.
• Insoluble fiber does not dissolve in water. Instead, it adds bulk to stool and helps food move through your digestive system, supporting regular bowel movements. You’ll find it in whole grains, nuts, leafy greens, and the skins of fruits and vegetables.

Most plant-based foods contain a mix of both, so eating a variety of fiber-rich foods helps you get the full benefits.

Everyone should consume both types,

Stern adds, noting that people shouldn’t worry too much about getting more of one than the other. Many foods contain both types, just in different proportions.

In its different forms, fiber is something of a miracle worker. In addition to keeping you regular and supporting your gut microbiome balance, it helps manage blood sugar and cholesterol, reducing both heart disease and type 2 diabetes risk. It also keeps you fuller longer, so it plays a role in healthy weight maintenance. While we still don’t understand the precise mechanisms through which fiber influences health, one 2024 study concluded that dietary fiber “plays a pivotal role in mitigating the risk of several chronic diseases” and suggested policy changes to increase access to affordable, nutritious, fiber-rich foods, particularly in underserved areas.

As Stern puts it, “If there’s something you’re going to “max” out on, fiber is certainly up there.”

But not everyone should be fibermaxxing. In some cases, too much of a good thing can be bad. People with certain gastrointestinal conditions, such as Crohn’s disease, ulcerative colitis or irritable bowel syndrome, are usually on fiber-restricted intake. What’s more, some people may find that loading up on fiber irritates their digestive system, leading to bloating and diarrhea.

“Generally speaking, if you have a GI condition or a certain medical history, you should meet with a dietitian [about changing your diet],” he says.

Even for healthy individuals, there is a right way — and a wrong way — to load up on fiber.

Stern suggests:

• Start low and slow. In other words, don’t go from eating 5 grams of fiber daily to 25 grams in one fell swoop. There will be, as Stern describes it, “consequences.” Instead, start by adding ½ cup of a fiber food once a day. After two weeks, increase that to ½ cup of fiber twice a day, and then three times a day.
• Hydrate, hydrate, hydrate. “You need to drink lots of water to help fiber move through your system,” he says.
• Seek variety. Consume different colors of fruits and veggies, what dietitians call “eating the rainbow.” Fruits and veggies get their colors from plant compounds called phytonutrients and each provides unique health benefits.
• Chew your food well. Don’t race through a meal. Aim to grind down every biteful to the consistency of applesauce before you swallow. Reducing food to tiny particles helps break down the cellulose of fiber cell walls, releasing vitamins and minerals. It’s also easier on your digestive system and helps signal when you’re full.
• Go for texture modification if you have a sensitive gut or a GI condition. This means changing the form of the food by blending, grinding or cooking it. This allows for easier digestion. Examples: eat a veggie soup instead of salad. Or try hummus instead of chickpeas, cooked broccoli over raw.
• Aim for naturally occurring fiber over packaged food with high-fiber labels. Packaged foods, even if they meet the fiber guidelines per serving, are packed with preservatives, emulsifiers and other additives. That said, Stern says flexibility is the key. “Sometimes our choices are limited,” he adds. “If you’re in the airport and your only options are between a bag of potato chips and a high fiber bar, by all means choose the bar.”

Written by Ana Veciana-Suarez.

Tags: digestive health tips, gut health and fiber, microbiome health, nutrition care in Miami