Nick NorwitzMD PhD, Oxford-Harvard | Metabolic Health Educator | “Stay Curious”

When Fiber Harms the Gut (And Meat Heals It)

26 Jul 2026 · 1 min

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1:24

In this monologue, Nick Norwitz argues that dietary fiber can be detrimental for certain individuals, particularly those with constipation‑type irritable bowel syndrome (IBS) and severe inflammatory bowel disease (IBD). He cites a 2012 study showing that eliminating fiber increased bowel movement frequency and reduced bloating in IBS patients. He then presents a case series of ten patients with treatment‑resistant ulcerative colitis or Crohn’s disease who achieved remarkable improvement on a zero‑fiber carnivore diet, with patient interviews describing life‑saving effects. Norwitz references additional mechanistic animal studies and reports remission rates of 60‑85% in treatment‑resistant IBD after fiber elimination. While emphasizing that the carnivore diet is not a universal cure, he urges clinicians and patients to consider it as a viable, curiosity‑driven option when conventional therapies fail, suggesting that today’s fringe approaches may become tomorrow’s standards of care.

Chapters

Fiber can harm the gut for some people, and meat may heal it. Stay with me because there are real nuances here. First, let's start with a simple question: Do you need fiber to poop? That one's easy—no. In fact, in a 2012 study, people with constipation-type irritable bowel syndrome went from having 4 bowel movements a day to a bowel movement every single day when they eliminated fiber, along with less bloating and straining. Okay, that's interesting, but here's where things get serious. Consider people with severe inflammatory bowel disease, ulcerative colitis and Crohn's disease, people who have been on harsh drugs and sometimes have had parts of their intestines removed. Well, colleagues and I published a case series on 10 such people who responded remarkably well to a zero-fiber carnivore diet, and this wasn't just hearsay but validated medical cases. And in their patient interviews, they said carnivore saved their lives and that the decades they'd spent deathly sick felt like another lifetime. And there were more data to support this as well, including mechanism papers in animal models and data showing that fiber elimination in human patients can cause remission in 60-85% of treatment-resistant inflammatory bowel disease cases. Now, that does not make carnivore a cure-all, but for patients who are suffering and for whom conventional medicine has continually failed, anything that works deserves curiosity, not ridicule. And remember, sometimes today's fringe is tomorrow's standard of care. And I bet you know someone who needs to hear that.