What food scientist Matt Amicucci wants you to know about fibermaxxing

For something that spent decades as a nutritional afterthought, fiber has become an unlikely obsession. It turns up now in chia puddings, psyllium drinks, and in the daily gram counts on social media trends that follow people loading up on high-fiber foods. The name behind the trend? Fibermaxxing.

Matt Amicucci, a food scientist who has studied fiber for fifteen years and co-founded the wellness company one.bio and its consumer brand GoodVice, has been watching the trend unfold. But he argues that the conversation has narrowed around the wrong thing.

We spoke with Amicucci about what fibermaxxing gets right, what fiber actually does once it hits the gut, and how to eat it in a way that noticeably changes how you feel.

What fiber is actually doing in your gut

Fiber has long been reduced to its most obvious job: keeping digestion moving. Amicucci does not dispute that, but he sees it as the least interesting part of the story. A more useful way to think about fiber, he says, is as something that helps direct activity in the gut rather than simply pass through it.

When the right fibers reach the microbiome, they help trigger compounds involved in inflammation, metabolism, and immune function. “Fiber doesn’t just help things move,” he says. “It helps coordinate how the body responds.”

That is where the daily gram count starts to fall short. Fiber, he points out, was never a single substance to be tallied the way we count protein. It is a broad family of molecular structures, and the kind you eat matters far more than the amount, because structure is what determines what fiber does once it reaches the gut.

Why “fiber” is too simple a label

The misunderstanding Amicucci runs into most often is the idea that fiber is one nutrient, something you either get enough of or you do not. He prefers to think about it more like vitamins.

“Nobody treats vitamin as one substance, because vitamin A and vitamin C are both essential and do almost nothing alike,” he says. “Fiber works the same way.”

Those structures do not all do the same job. One may help steady blood sugar, another may temper inflammation, and another may feed a narrow group of microbes while leaving the rest alone. “Its structure determines which microbes respond and what signals get produced,” Amicucci says. A label that lists “fiber” as a single line item tells you a category showed up, not what that fiber came to do.

The only way fiber can work

Before earning a PhD in agricultural and environmental chemistry, Amicucci spent close to a decade cooking in restaurant kitchens across Europe and the United States. The kitchen taught him something the lab later confirmed: a food only matters if people want to eat it again.

“If it doesn’t taste good, no one’s going to eat it twice,” he says. Fiber is no exception.

It sounds obvious, but he thinks the wellness industry has spent years ignoring that reality, treating nutrition as a choice between food that is good for you and food you actually want. He does not buy the trade-off. Health depends on habit, and habit depends on enjoyment, which means the science that makes a fiber effective is only half the job. The other half is turning it into something a person reaches for without being told to.

That idea also shaped GoodVice, which he built around the premise that metabolic support should show up in food people would want anyway.

Why the right fiber can change how you feel

Walk down any grocery aisle and the word “fiber” appears on dozens of labels. But Amicucci points out that many added fibers are there for practical reasons, not biological ones: they are cheap, easy to formulate, and useful for hitting a target number on a nutrition panel. Many also, in his words, “ferment rapidly and indiscriminately” once they hit the gut, which helps explain why so many supplements leave people bloated.

The fibers worth paying attention to, he argues, are the ones chosen for what they actually do. One.bio’s lead ingredient, 01, was identified in oats because its molecular structure feeds the microbes that produce butyrate. That matters because butyrate acts as a powerful anti-inflammatory signal and helps regulate the gut-brain axis.

In clinical studies, two weeks on that specific fiber improved both glucose response and mood. The shift in mood and focus traces back to lower systemic inflammation, while the steadier energy comes from a more measured release of GLP-1, helping blunt the spikes and crashes that tend to follow a fiber-poor diet.

Where to go from here

For all the molecular detail, Amicucci’s advice is fairly straightforward. Most Americans, by his estimate, are not getting anywhere near enough fiber, so the first move is not optimization. It is building a habit that can actually last.

Start with whole foods, where fiber arrives in the range of structures the gut is built to handle. If you want to supplement beyond that, look for fibers with real evidence behind them, like the beta-glucans found in oats and barley, rather than whatever ingredient was cheapest to add.

His one firm rule is about fit. “The right fiber is one you can consume consistently and comfortably,” he says, because a fiber that bloats you or bores you is a fiber you will eventually stop eating.

Underneath all of this is a simpler reframe. Fibermaxxing treats fiber as a number to push higher. Amicucci would rather you treat it as something to get right, choosing the structures your body can actually use and eating them in a way you can stick with. Do that, and the grams stop being the whole story.