Fibremaxxing: Does more fibre make you healthier?

But this is one trend that has the right idea. Most adults in the UK are only getting around 20 grams of fibre a day — that’s 10 short of the recommended 30 g.

Getting enough fibre can make a big difference to your long-term health. Eating a high-fibre diet is associated with lower risks of cardiovascular disease, type 2 diabetes, bowel cancer, and a lower risk of depression.

If we zoom in a little further, we see that it can have a meaningful impact on your blood markers, playing a role in blood sugar management and blood lipids, like LDL cholesterol. Getting enough fibre can also help lower your blood pressure if yours is already high.

Some people find it hard to get 30 g of fibre daily, which is why the encouragement and inspiration provided by the concept of fibremaxxing are welcome. Like most healthy eating trends, however, these can make it easy to see a specific dietary change as a magic bullet.

How much difference does suddenly increasing your fibre intake make? A recent study using Thriva’s home blood tests set out to investigate just that. Let’s take a look.

What’s the impact of an extra 10 grams of fibre a day?

In this 2026 study, published in The Journal of Nutrition, Health and Aging, the researchers wanted to see how eating an extra 10 g of fibre a day for 12 weeks affected older adults who typically ate around 16-17 g of fibre a day.

Extra fibre came in the form of a fibre-enriched white bread roll. A control group received a white roll that had the same taste, appearance, and calories but not the added fibre.

The researchers were primarily interested in seeing how eating more fibre might affect cognitive function, but they also measured mood, gut symptoms, and blood markers to see if there were any effects there.

After 12 weeks, the researchers found that most cognitive, mood, and biological outcomes were unchanged after eating the fibre-enriched bread.

The only significant difference associated with eating the high-fibre rolls was a decrease in hostility. Interestingly, the control group was associated with improvements in memory and an increase in HDL cholesterol.

According to the authors of the study, this was unexpected, and we shouldn’t take it as proof that eating less fibre improves memory. There are other factors that could be at play — like how freezing the rolls impacted the resistant starch content — that mean more research is needed.

The limitations of adding in a single high-fibre food

The researchers found that the fibre intake of the participants did not change across the 12 weeks of the study, nor did it differ between the control group and the group eating the high-fibre rolls.

However, they did find that fortifying the bread with prebiotics was feasible. On the whole, people in the study did a good job of sticking with it, which is a positive sign.

This outcome means the study shows us the effects of adding a single particular food into a diet rather than the impact of extra fibre.

It’s interesting that the group eating the fortified roll didn’t increase their overall fibre intake, and we don’t know how the rest of their diets might have changed during the trial. It’s a classic challenge when it comes to studying people whose lives don’t change outside a single intervention, and it affects a lot of nutrition research.

Our conclusion here is that if you want to increase your fibre intake, the evidence suggests it may be better not to rely on a single high-fibre food. Adding several new foods can be easier to stick to in real life.

Note: This study was funded by Innovate UK and the Biotechnology and Biological Sciences Research Council, and Thriva tests were used in the study. One of the authors was an employee and shareholder of prebiotic fibre company Myota.

There is more than one kind of fibre: Soluble vs. insoluble

When we talk about fibre being good for you, it’s easy to start seeing it as one thing. But there are different types of fibre, and getting a range of them in your diet is important.

You may be aware of the distinction between soluble and insoluble fibres. Soluble fibre pulls in water and forms a gel that can help slow digestion. Insoluble fibre does not, instead adding bulk to your stool. Two different classes of fibre that can provide separate benefits.

It’s not just a matter of soluble vs insoluble fibre either. Different fibre types will ferment in the gut in different ways, have different levels of viscosity, and form different kinds of gels (if at all) in the gut.

The fibre in the enriched roll was prebiotic fibre. This type of fibre acts as a source of fuel for beneficial microbes living in your gut, supporting the growth or activity of specific microbes. Different types of prebiotic fibre support different beneficial microbes.

All these kinds of fibre support your health in different ways. As a result, there’s a range of benefits to be had getting your fibre from a variety of places.

Note: Prebiotic fibre is not the same as probiotics, which are live microbes that can have a beneficial effect on your health.

The benefits of getting fibre from whole foods, not supplements

While supplements will provide you with some specific types of fibre, whole foods can provide a much wider range. They also contain beneficial vitamins, minerals, and nutrients.

The fibremaxxing trend has involved people sharing different ways of increasing fibre on your plate through adding or swapping in whole foods, but there can also be pressure that could steer people down the supplements route.

It’s true that there are plenty of occasions where a fibre supplement may be the way to go, such as when:

• you’re trying to relieve chronic constipation
• you’re only able to tolerate soft foods
• barriers limit your access to dietary sources

If you experience persistent or new constipation, check with a doctor before changing your diet or taking fibre supplements. It could be a sign of an underlying condition that needs checking first.

But if you are able to go down the whole foods route, you have the most potential benefit. Similarly, fibre-enriched foods, like the bread rolls in the study, can make it a little bit easier to add fibre while reaping the benefits of whole foods.

How to increase your fibre intake in a healthy and effective way

As a starting point for increasing your fibre intake, you could look at the meals that you have most often throughout the week.

Pick one or two meals and see how you might be able to increase their fibre content, either by swapping ingredients or by adding in something extra. It could be as simple as swapping white pasta for brown, or sprinkling a serving of seeds over the dish.

Here are some other key considerations for when you’re looking to increase your fibre intake with whole foods:

• Take your time: Your body needs time to adjust to higher amounts of dietary fibre. Suddenly going from 20 g to 40 g a day could lead to uncomfortable gut symptoms, so be sure to increase how much you eat gradually.
• Drink plenty of fluids: The more fibre you consume, the more fluids your body needs in order to process it properly. Aim for 6-8 glasses a day, and honour your thirst cues as and when they appear.
• Don’t forget other food groups: Try not to let your focus on fibre overshadow other nutritional needs. In addition to getting your fibre from a range of different sources, aim to include sources of protein and healthy fats throughout your day.

If you’re trying to identify high-fibre foods at the shop, look for ones that provide at least 6 g of fibre per 100 g.

While many products will have “high fibre” somewhere on their packaging, it’s not a guarantee. Sometimes you’ll find foods that claim to be high in fibre, but really aren’t at all.

The British Nutrition Foundation has some handy info on how much fibre is usually in common foods and meals on its website.

If you’re curious how increasing your fibre intake might be impacting health markers like LDL cholesterol, HbA1C, or hs-CRP, you can track these over time with blood tests.

Own your health with home blood testing, doctor reviewed results, and sustainable lifestyle guidance.

How to increase your fibre safely

Eating more fibre is generally a good idea, but it’s not safe for everyone. Before adding more fibre to your diet, bear these things in mind:

• Avoid doing so if you have known or suspected inflammatory bowel disease, bowel obstruction, strictures, severe gastroparesis, or swallowing problems
• Speak with a doctor if you have a change in bowel habits, rectal bleeding, unexplained weight loss, vomiting, or anaemia
• Consider splitting up doses of oral medications
• If you have IBS, choose soluble fibre instead of insoluble, which can cause pain and bloating

Takeaway

The fibremaxxing trend has encouraged people to eat more fibre, which is a sensible thing to do considering that it’s beneficial for your health and most adults aren’t getting enough of it.

If you’re looking to increase your fibre intake, however, try not to rely on adding one single high-fibre food to your diet. If you can, get your fibre from multiple whole food sources rather than supplements, take your time in scaling up, and make sure you’re drinking enough fluids as you go.

Frequently asked questions

How much fibre should you eat a day?

The UK recommendation is 30 g a day, and most adults get around 20 g. Closing that 10 g gap is the part of fibremaxxing worth taking seriously, because a high-fibre diet is associated with lower risks of cardiovascular disease, type 2 diabetes, and bowel cancer.

Can you eat too much fibre?

Going up too fast is the more common problem. Jumping from 20 g to 40 g in a few days can leave you bloated and uncomfortable, so build up gradually and drink more fluid as you go.

Increasing fibre isn’t suitable for everyone. If you have inflammatory bowel disease, a bowel obstruction or stricture, severe gastroparesis, or swallowing problems, speak to a doctor first.

Are fibre supplements as good as whole foods?

Whole foods give you a wider range of fibre types alongside vitamins and minerals, so they’re the better default. Supplements still have their place, including for chronic constipation, soft-food diets, or where getting to dietary sources is difficult.

If your constipation is new or persistent, check with a doctor before you start.

How long does it take to see a difference?

Gut symptoms from a gradual increase usually settle as your gut adapts. Blood markers move more slowly: HbA1c reflects roughly three months of blood sugar, so give any change eight to 12 weeks before you retest and look for a shift.

Disclaimer: This information is for general educational purposes only and isn’t a substitute for professional medical advice, diagnosis, or treatment. Always discuss new supplements with a qualified healthcare professional if you take regular medications or have medical problems, or have questions about your health. If you’re having a medical emergency, please seek help by contacting your local emergency services.