343: What is Fibermaxxing and Why is My Grandma Talking About It?

Fibermaxxing: Both Sides of the Argument   97% of men in the US don't meet their daily fiber requirements. Not most men. 97%. And yet Gen Z is suddenly obsessed with maximizing fiber intake, at the exact same time that colon cancer rates in adults under 50 are rising at 3% per year. That timing isn't a coincidence. In this episode we break down where fibermaxxing came from, what the science actually says, and where the carnivore counter-argument holds up and where it falls apart. What we cover: What fibermaxxing actually is, and why the 30-plants-a-week movement behind it traces back to a 2018 study involving over 10,000 citizen scientists The fiber gap: 97% of men and 90% of women aren't hitting daily targets, so "maxxing" sounds extreme when most people are just trying to close a massive deficit Steph Grasso, the RD with 2M TikTok followers who claimed 2024 as "the year of fiber" and why her comment section is a perfect case study in how people misread their body's response to fiber Why "fiber bloats me" is almost always a transition problem, not a verdict, and the ramp-up approach that fixes it Butyrate: the mechanism most people have never heard of. Fiber feeds bacteria that produce it, and it's the primary fuel source for your colon cells with documented anti-cancer properties The colon cancer data in young adults: people born around 1990 are twice as likely to get colon cancer and four times as likely to get rectal cancer as those born in 1950 The Hadza tribe research: one of the last hunter-gatherer populations on earth, eating roughly 150g of fiber a day, with 40% more gut microbial diversity than Americans The carnivore counter-argument, taken seriously: the IBS and Crohn's evidence is real, and the question of why you'd prioritize something indigestible deserves a real answer Why Gut Reset exists: prebiotics build the foundation before probiotics can take hold, and skipping that step is why most probiotic attempts don't stick The Chris Reed connection: how starting each meal with a fibrous food helped him reverse his diabetes markers, and why it's the simplest application of this science Referenced in this episode: Chris Reed diabetes reversal episode Gut Reset  Prof. Tim Spector / ZOE: zoe.com Steph Grasso: @stephgrassord on TikTok Netflix: Hack Your Health American Gut Project (2018) The takeaway: You don't need to chase 100 grams a day. But if you've been avoiding fiber because it bloats you, you likely quit before your gut had a chance to adapt. Give it four weeks done right, and see what happens.