How to Get 25 g of Fibre a Day Without the Bloating

Aim for at least 25 g of fibre a day, and get most of it from 1 to 2 fists of veg at every meal. Legumes, oats, whole grains and berries cover the rest, and building up slowly with plenty of water keeps the bloating short-lived.

No bran cereal required. And no, you don't have to choose between your protein and your gut.

Why 25 g of fibre a day?

Because that's where the research says the payoff sits.

A large series of reviews in The Lancet, pooling prospective studies and 58 clinical trials, found the biggest risk reductions at 25 to 29 g a day. People who ate the most fibre had 15 to 30% lower rates of death from any cause and from heart disease, plus less coronary heart disease, stroke, type 2 diabetes and colorectal cancer, compared with those who ate the least. Some data suggest going past 30 g adds more.

That's not a gut "wellness" trend. That's harder to kill.

Where does fibre actually come from?

Mostly from veg. 1 to 2 fists at every meal gets you most of the way. Veg are carbs too, and they belong on every plate.

Then add one of these daily:

• oats at breakfast
• a scoop of beans or lentils
• a cup of berries

Fibre comes in two main types, and you want both:

• Soluble fibre (oats, beans, psyllium) absorbs water and softens stool.
• Insoluble fibre (many non-starchy veg, wheat bran) adds bulk.

My perimenopause people: the rule is protein and veg first, starch last, at every meal. Your fibre and your blood sugar both win. More on that in [Blood Sugar Spikes in Perimenopause](/blog/blood-sugar-spikes-perimenopause).

Why am I bloated after eating more veg?

Because your gut is adjusting. Totally normal.

Raising fibre quickly can bring a couple of weeks of extra gas, gurgling and bowel changes. It does NOT mean your body "can't handle fibre". It means you went from zero to hero on a Monday.

What to do:

• Ease back a little and build up more slowly.
• Drink more water.
• Slow down and chew. Eating fast means swallowing air and taking bigger bites.

Some foods rich in FODMAPs (some beans, onions, garlic, wheat, some fruit) cause gas and bloating in sensitive people. Lactase can help with dairy, and alpha-galactosidase can help with beans. If one specific food bothers you, deal with that food. Don't drop a whole food group. Carbs aren't cut here. Ever.

When you're two weeks in, the noise settles down. Most people forget it was ever a thing.

Does a high-protein diet cause constipation?

Rarely on its own. What usually happens: protein crowds out the veg, the fibre and the water. Then everything backs up and the protein gets blamed.

So keep your four protein meals at 30 to 40 g each (why that matters is in [Does Collagen Count as Protein?](/blog/does-collagen-count-as-protein)). Then:

• Put 1 to 2 fists of veg next to every protein serving.
• Add a glass of water at each meal.
• A shake counts as a meal only if it reaches 30 g of protein. Add fruit, oats or a spoon of psyllium to boost its fibre.

Simple checklist for constipation: fibre around 20 to 35 g a day, move every day, and drink enough. Do NOT skip meals or cut protein to "rest your gut". That's not a fix, that's a new problem.

Is cold rice actually better for your gut?

Yes, a little. And it's the laziest meal-prep win there is.

Cook potatoes, rice, pasta or beans ahead, chill them overnight, then eat them cold or gently reheated. Part of the starch becomes resistant starch, which feeds your gut bacteria.

In a small study of 15 healthy adults, white rice cooled for 24 hours and then reheated had about 2.5 times the resistant starch of freshly cooked rice, and a modestly lower blood sugar response. Honest: the blood sugar effect is small and the data are limited. But it costs you nothing except cooking on Sunday.

Should I eat fermented foods?

They're worth adding. Just don't expect a miracle.

In a 10-week Stanford trial of 36 healthy adults, a diet high in fermented foods (yogurt, kefir, kimchi, sauerkraut, kombucha, aiming for about 6 servings a day) increased gut microbiome diversity and lowered 19 inflammatory markers in the blood. The high-fibre group didn't see those changes in 10 weeks. Stanford's Justin Sonnenburg talked this through on Huberman Lab, and the practical takeaway was to add a few servings of low-sugar fermented foods each day.

Now the fine print, because I don't do hype. The study was small and in healthy adults. Higher diversity hasn't yet been shown to lower disease risk, and the lead investigator called the results "not ready for prime time" for diet prescriptions. Kefir has the strongest evidence, mostly for heart and metabolic health rather than digestion.

And fermented foods are not the same as probiotic pills. The Stanford trial used whole foods, and most of the new microbes didn't even come from the foods themselves. Food first.

What about psyllium?

Optional. 5 g in water before your two biggest meals. Build up over 2 weeks, drink plenty of water, and take any medications at a different time of day. If constipation hangs on despite a varied, plant-rich diet, talk to your doctor before adding it, because in some people it makes gas, bloating or diarrhoea worse.

Curious about probiotics or digestive enzymes? Food and lifestyle first, then supplements, then a naturopathic doctor. My full take is in [Which Supplements Are Worth Taking After 40?](/blog/which-supplements-worth-taking-after-40).

When is bloating a doctor problem?

Occasional bloating is common. Bloating most days for weeks is not "just getting older".

This isn't medical advice. See your doctor promptly if you have bloating on most days for about 3 weeks, especially with feeling full quickly, tummy or pelvic discomfort, needing to pee more often, or bowel changes in women over 50. These can be early signs of ovarian cancer. Same goes for blood in your stool or black stools, unexplained weight loss, a lasting change in bowel habit, vomiting, severe or night-time pain, difficulty swallowing, fever with gut symptoms, or any bleeding after menopause.

Quick answers

How do I get to 25 g of fibre a day? Start with 1 to 2 fists of veg at every meal. Then add oats at breakfast, a scoop of beans or lentils, or a cup of berries each day.

Is it normal to feel bloated after adding fibre? Yes, for the first couple of weeks while your gut adjusts. Build up slowly, drink more water and chew slowly.

Does high protein wreck digestion? The usual problem is too little veg, fibre and water alongside it. Keep the protein, add veg and a glass of water at each meal.

Should I cut carbs to stop bloating? No. A specific food may bother you, and that's worth looking at, but it's not a reason to drop a food group.

Are fermented foods the same as probiotics? No. The Stanford trial used whole fermented foods, and most of the new microbes didn't come from the foods themselves. Food first.

Sources. Reynolds A, et al. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet. 2019. Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021. Center for Science in the Public Interest. Do fermented foods or fiber improve your gut microbes? Sonia S, et al. Effect of cooling of cooked white rice on resistant starch content and glycemic response. Asia Pacific Journal of Clinical Nutrition. 2015. Precision Nutrition. How to improve your gut health and microbiome. Precision Nutrition. Research review: Can lowering fiber intake help with constipation? (reviewing Ho KS, et al. World Journal of Gastroenterology. 2012). Huberman Lab Podcast. Dr. Justin Sonnenburg: How to build, maintain and repair gut health. 2021. NI Direct. Recognising signs and symptoms of ovarian cancer.