TikTok’s latest health trend has influencers cramming fiber into everything like it’s protein powder circa 2015. They call it “fibremaxxing” — the idea that more fiber equals better health, with some pushing followers toward 100g daily.
The fiber enthusiasm isn’t misplaced. Most of us barely hit half the recommended 25-35g daily, missing out on fiber’s impressive longevity benefits: better insulin sensitivity, lower inflammatory markers, and gut bacteria that actually produce beneficial metabolites instead of just existing.
But 100g daily? That’s where Instagram wellness meets biological reality.
Dr Emily Leeming, a dietitian at King’s College London, points out that our Paleolithic ancestors might have managed 100g of fiber daily — but they also had different gut microbiomes and weren’t suddenly jumping from 15g to 100g overnight.
Your modern gut, adapted to processed foods and chronic under-consumption of plants, will revolt. Think bloating, gas, and digestive distress that makes you want to go back to white bread forever.
The sweet spot seems to be gradual increases toward 40-50g daily. That’s enough to feed beneficial bacteria, improve short-chain fatty acid production (the real longevity magic), and support healthy glucose metabolism without turning your intestines into a fermentation experiment.
The fiber-longevity connection is solid: higher fiber intake correlates with reduced all-cause mortality, better metabolic health, and healthier aging. But like most things in biology, the dose-response curve isn’t linear. More isn’t always better when your gut bacteria are staging a rebellion.
Start with an extra serving of vegetables, add some berries, maybe switch to whole grains. Let your microbiome adapt over weeks, not days.
The Protocol says: Aim for 40g daily, built up slowly over months. The longevity benefits are real, but your gut needs time to adapt. Skip the extreme fiber loading — sustainable wins over spectacular.
The fibremaxxers got the destination right, just not the route.
Analysis draws from The Guardian’s coverage of the “fibremaxxing” trend and expert commentary from King’s College London.