Is it true that … you can never eat too much fibre?

Fibremaxxing is everywhere, and most of us should eat more roughage, but your gut won’t thank you for overloading

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ibre has replaced protein as TikTok health influencers’ macronutrient du jour, with “fibremaxxers” urging followers to pack as much roughage into their diets as possible. But is the sky really the limit?

“In theory,” says Dr Emily Leeming, a dietitian at King’s College London and the author of Fibre Power (out in May): our ancestors may have eaten up to 100g of fibre a day, but that’s far beyond what most modern guts can tolerate.

Fibre is found in nuts, seeds, leafy greens and beans, and can be taken as a supplement. The average Briton eats about 16g a day – little more than the recommended amount for two- to five-year-olds – and only 4% hit the 30g adult target. Leeming says reaching that level could have significant benefits: “Fibre supports digestion, lowers the risk of bowel cancer and heart disease, reduces low-density lipoprotein (or ‘bad’) cholesterol, helps control blood sugar, and promotes fullness.”