The self-quantified, data-to-action human.
Fibermaxxing is the trend that made fiber interesting again: chia puddings, psyllium in everything, bean-heavy bowls, and a target of 30 g a day or more. Its pitch is better digestion, steadier blood sugar, longer fullness, and a healthier gut. Unlike most of the "-maxxing" family, the core idea has real backing: the US dietary guidelines ask for about 14 g of fiber per 1,000 kcal eaten, and most adults fall well short.
The question I can actually answer is whether I fall short. I log food in my own athlete system, and between July and October 2026 that is 712 entries over 110 days. Many of those days were logged as rough calorie estimates rather than item by item, so I took only the 36 days I logged food by food and ate more than 1,500 kcal.
The number: about 14 grams
On a median of about 2,600 kcal a day, the guideline works out to roughly 36 g. I hit a median of 14.3 g, and my best day was 33 g. Fibermaxxing isn't something I overdo. It's something I'm not doing at all.
One caveat makes the log look worse than reality. Some café and restaurant items have no fiber value attached, so they count as zero. Even if those entries doubled the total, I would still be at about 10 g per 1,000 kcal, under the guideline.
Where my fiber actually comes from
| Food | Fiber per serving | Role |
|---|---|---|
| Rolled oats (½ cup dry) | 4.0 g | Biggest single source in the log |
| Weetabix (per biscuit) | 1.9 g | The most-logged fiber food |
| Morning shake (whey, almond milk, chia, psyllium, creatine) | 10.4 g | Best per serving, logged only twice |
| Protein bar | 10 g | Mostly added fiber |
| Banana (medium) | 3 g | Usually pre-workout |
| Chia seeds (5 g) | 1.7 g | Small portions |
| Roasted sweet potato (café side) | 5 g | Occasional |
The pattern is obvious once it is in a table: almost all of my fiber comes from breakfast grains and a few fruits. Vegetables or legumes appear on 17 of 99 full-calorie days. The rest of the day is protein, and protein has no fiber. That is the cost of building every meal around a protein target, which I do on purpose during a GLP-1 course.
Why it matters more on GLP-1
GLP-1 drugs slow gastric emptying, and constipation is one of their most common side effects. During the femur recovery I had a plain rule for it: two days without a bowel movement means more water, more magnesium, more fiber. That rule was a fix after the fact. A steady fiber floor is what keeps you from needing it.
There is a catch the fibermaxxing videos skip. On a suppressed appetite, stomach space is the scarce resource. Fiber fills you up, which is the whole point for most people, but on GLP-1 a big bowl of beans can crowd out the protein I am trying to protect lean mass with. So for me, more fiber has to come in small, dense doses, not in volume.
My fibermaxxing plan, using food I already eat
- Make the morning shake the default. Whey, almond milk, chia and psyllium came to about 10 g of fiber in one glass. It is the densest fiber in my log, and it costs no stomach space at lunch.
- Oats every day, not some days. Days with oats or Weetabix had a median of 16.8 g. That is still low, but it is the base everything else stacks on.
- One vegetable or legume portion at lunch. The fix for the 17-out-of-99 problem is one side, not a new diet.
- Ramp slowly, with water. About 5 g more per week until I reach 25 to 30 g. Jumping straight there is how fibermaxxing turns into bloating.
- Low fiber before races. The pre-race meals go the other way, to easily digested, low-fiber carbs, as in my race-day fueling plan.
I will re-run these numbers after a month of the plan and update this page with the result, whether it moved or not. The sleep side of the same experiment is in Sleepmaxxing on 626 nights of data. Back to the Biohacking hub.
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