What Fibremaxxing Is

Fibremaxxing describes a deliberate push to eat more fibre than usual: adding legumes, whole grains, fruit, vegetables, nuts, seeds and sometimes fibre supplements, with the explicit goal of hitting a daily fibre target. It's been one of the more visible nutrition trends in Australian media through 2025 and 2026, picked up by dietitians as well as social media, which is a fairly unusual combination for a diet trend.

In practice, it tends to look like small, stacked changes rather than one big one: chia seeds stirred into breakfast, a second piece of fruit, legumes added to a dish that didn't have them before, wholegrain swapped in for refined. Some people track grams against a daily number the way others track steps or protein. The appeal is straightforward: fibre is one of the few nutrients where the average Australian diet falls clearly and measurably short, so there's real room for a small daily change to add up.

Why It's Had Dietitian Support

Most nutrition trends get a mixed reception from dietitians, often sceptical. Fibremaxxing has had more support than most, for a simple reason: the underlying advice, eat more fibre from a variety of plant sources, is advice dietitians have been giving for years anyway. The trend didn't invent new advice so much as put a name and a social momentum behind existing, uncontroversial guidance. That's also why the caution from the same dietitians is worth taking seriously: the advice they're uneasy about isn't "eat more fibre," it's the small minority of fibremaxxing content pushing numbers well past what any guideline recommends.

What It Gets Right

The gap is real. NHMRC's Adequate Intake for fibre is 30g a day for men and 25g a day for women, and most Australian adults don't reach it. A trend that gets people adding a second vegetable to dinner or swapping white bread for wholegrain is, in that specific respect, pointed at a genuine and well-documented shortfall, not an imaginary problem.

Where It Goes Too Far

Two things separate a reasonable fibre increase from an overcorrection: the target, and the speed.

On target: NHMRC's Suggested Dietary Target, the higher of its two benchmarks, tops out at 38g a day for men and 28g a day for women. Some fibremaxxing advocates recommend 50 to 100g a day, well beyond either NHMRC figure. NHMRC hasn't set a formal upper limit for fibre, and its review found no convincing evidence of harm at intakes up to 50g a day from a varied diet. That's a statement about safety at 50g, not an endorsement of 100g, and not a reason to treat "more" as a target in itself once you're well past the benchmarks that actually define adequate intake.

On speed: going from a low-fibre diet to a very high one quickly is the part most likely to cause genuine discomfort, regardless of the eventual target. A six-week trial of a high daily fibre dose found gas and bloating symptoms peaked in the first three weeks and eased back towards baseline by week six, at an unchanged dose throughout, which points to the gut adjusting over time rather than the amount itself being the problem. Jumping straight to a very high target skips that adjustment period, which is a large part of why some people try fibremaxxing for a week, feel uncomfortable, and conclude fibre itself doesn't agree with them, when the more accurate read is usually that the increase was too fast, not that the target was wrong.

There's also a simpler version of "too far": treating a single number as the whole picture. A diet built around one or two concentrated fibre sources, repeated daily to hit a target quickly, is a different thing from the same total spread across a variety of vegetables, legumes, fruit and wholegrains. NHMRC's own review noted that variety of source matters, separately from total amount. Fibremaxxing content that reduces the whole idea to "more grams, any way you can" skips that part.

The NHMRC Numbers

For adults, NHMRC publishes two fibre benchmarks: the Adequate Intake (30g a day for men, 25g for women) and the higher Suggested Dietary Target (38g for men, 28g for women). Neither benchmark is 50g, let alone 100g. If a specific number is useful as a target, these are the ones with an actual NHMRC rationale behind them.

A Gentler Way to Raise Intake

The practical version of fibremaxxing that holds up is the boring one: increase gradually, over weeks rather than days, and aim for NHMRC's benchmarks rather than an arbitrary high number. That might mean one new high-fibre food added each week rather than five at once, or a single daily addition kept consistent long enough for the gut to adjust before adding another. None of that photographs as well as a dramatic before-and-after, which is probably part of why it gets less attention than the extreme version of the trend, even though it's the version more likely to actually stick.

The underlying point is worth separating from the social media packaging it's currently wrapped in: smaller, sustained increases give the gut microbiome time to adapt, which is the difference between a fibre increase that sticks and one that gets abandoned after an uncomfortable first week. A prebiotic fibre supplement like DULCI, 7g of fibre per scoop, is one option among several for adding fibre without a new routine, used as a consistent daily amount rather than a single large dose.

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