What the Science Says About Getting the Most out of this Popular Social Media Nutrition Trend
“Fibermaxxing” is the latest internet trend with one basic message: eat more fiber.
And while the name is new. The idea is not.
Nutritionists and researchers have been telling people to eat more fiber for decades. But until recently, fiber has lacked a certain “sexiness” that often comes with the new age of health, wellness, and performance.
Fiber is a grandma supplement.
It took a social media movement and a hashtag to put fiber back where it belongs, in the spotlight and on the plate, at the foundation of nutritional health. But this isn’t as straightforward as many of the other movements.
“Fiber” is complex, and understanding its intricacies will help ensure you truly max Fibermaxxing.
What is Fiber, Actually?
The term “fiber” gets thrown around a lot, like it’s just a singular nutrient. But it’s a bit more complicated than that.
Generally speaking, fiber is an overarching term for plant carbohydrates that the body can’t digest. Each type of fiber has a special role and is categorized based on how it behaves in the body (1).
There are three main ways fiber is characterized:
- Soluble fiber. Dissolves in water and forms a gel in the gut. Found in oats, beans, apples, barley, and psyllium. It slows digestion.
- Insoluble fiber. Doesn’t dissolve in water and adds bulk while helping to speed transit time, making it the regularity workhorse. Found in wheat bran, whole grains, vegetable skins, and nuts.
- Fermentable fiber. Food for your gut bacteria. Inulin, resistant starch, and beta-glucans.
It is important to note that singular fiber sources often possess multiple characteristics. For example, beta-glucans are both a soluble and fermentable fiber. Finding balance and consuming fibers with a variety of characteristics is the key to getting the most out of this nutritional category.
What Are the Benefits of Eating Fiber?
Gut health. As mentioned above, fiber is the main fuel for the bacteria in your colon. Consuming it helps shape a healthier microbial community and diversity, promotes a healthy intestinal barrier, and leads to the production of short-chain fatty acids that feed colon cells and help regulate inflammation (2).
Glucose control. Fiber slows the rate at which carbohydrates enter the bloodstream. A 2023 longitudinal study looking at the association between fiber intake in healthy individuals demonstrated that eating more fiber was associated with lower blood glucose markers and higher insulin sensitivity.
This is more than an association. A 2024 study examining the effects of fiber consumption on markers of blood glucose dynamics showed that consuming barley dietary fiber prior to glucose helped blunt blood glucose concentrations and insulin responses, again, in healthy people.
Weight management. Fiber distends the stomach, slows gastric emptying, and triggers satiety hormones. Basically, it makes you feel full. A meta-analysis in Obesity Review found that increased fiber intake reduced appetite and food intake, with modest reductions in body weight (3).
Cholesterol management. Soluble fiber supports healthy cholesterol levels. A 1999 meta-analysis of 67 controlled trials found that 2 to 10 grams per day of soluble fiber produced consistent reductions in total and LDL cholesterol (4). The dosing depends on the fiber. Three grams of oat or barley beta-glucans have been shown to promote changes (5), while it takes roughly 10 grams per day of psyllium to elicit benefits (6).
Supports longevity. A 2019 meta-analysis in The Lancet tracked the long-term outcomes of people who hit it. Across pooled prospective studies, those eating 25 to 29 grams per day showed 15 to 30% lower rates of premature mortality and major cardiometabolic conditions compared to the lowest-intake group (7).
How To Actually Maximize Fibermaxxing
How much? A 2019 series of meta-analyses in The Lancet identified the sweet spot at 25 to 29 grams per day, with continued benefit up to roughly 35 grams (7).
Where to get it. Vegetables, fruit, whole grains, oats, legumes, nuts, and seeds. Supplements like psyllium and inulin work in a pinch but don’t replace the needed variety that real food provides.
Ramp up. For those who aren’t making the cut and looking to add, DO NOT GO ALL IN IMMEDIATELY. Your gut is going to hate you. Take it slow; adding about 5 grams daily per week is a great way to ease into it. Make sure to drink more water as you do.
Practical split. No major nutrition body has a set fiber guideline that officially splits fiber by type, but based on the research, a decent working framework can be established.
First, make sure you are hitting your total target (25 to 35 grams daily). From there, aim for 5 to 10 grams of soluble fiber and 5 to 7 grams of fermentable fiber per day. The rest tends to land as insoluble by default if real food is doing the work. Remember, fiber sources can have more than one characteristic.
Maxing Fibermaxxing
“Fibermaxxing” is a shiny title draped over a recommendation that research has supported for decades.
By understanding the complexities and sticking to the guidelines of eating between 25 and 35 grams of a variety of fiber sources, Fibermaxxing can be maximized, and lasting benefits can be realized.
Author Bio:
Dr. Vince Kreipke, "Dr. K", received his PhD in Exercise Physiology with a focus in Sports Nutrition in 2016 from Florida State University, where he studied the effects of various dietary and exercise interventions on performance and metabolism. Since then, he has expanded his research to include ways of optimizing cognitive performance, general well-being, and longevity. Currently, Dr. K works one-on-one with clients, helping them in realizing their physical and cognitive potential, and as an advisor to companies within the health and performance industry, aiding in educational efforts and the development of safe and efficacious dietary supplements.
