Fibre was never destined to be the sexy rockstar of the wellness world… until fibremaxxing came along. While we don't usually head to TikTok for wellness advice, the fibremaxxing trend – where you up your fibre intake – actually makes a lot of sense. Fibre is best known for preventing constipation...so, as we say, not exactly sexy. But getting enough fibre is important as this nutrient comes with some impressive health benefits, not least lowering your risk of heart disease and bowel cancer.
"Fibre is important for digestion to keep everything moving through your digestive tract and also to help feed the bacteria in your gut," says Rob Hobson, a nutritionist and author of the book “Unprocess Your Life: Break Free From Ultra Processed Foods For Good”. “It also has many other health benefits, and proven ones at that: fibre supports blood sugar balance, lowers cholesterol and keeps you feeling full.”
In this article:
→ What is dietary fibre?
→ Why do you need fibre?
→ Soluble vs insoluble fibre
→ How much fibre should you eat every day?
→Signs that you're not getting enough fibre
→How to get more fibre - quick hacks
What is dietary fibre?
“Fibre is a kind of carbohydrate exclusively found in plants,” says Rhian Stephenson, nutritionist and founder of Artah Health. So a diet with plenty of beans, lentils, vegetables, nuts, seeds, whole grains (like oats, barley and buckwheat) and fruit will naturally be high in fibre, she notes.
Why do you need fibre?
We need fibre in our diets for a few reasons. Fibre is the part of the plant that our digestive system can’t break down (this includes cellulose, hemicellulose, pectin, lignin, beta-glucans, and gums).
“We don’t have the enzymes needed to digest them, but that is why they are so beneficial," Rob notes. “Because fibre resists digestion, it travels through the gut intact, where it helps to bulk out stool and slow the release of glucose [blood sugar] into the bloodstream.”
Fibre is also the main source of fuel for the good bacteria in our guts, says Rhian. “Fibre passes through the GI tract into the colon relatively unchanged where it ferments and produces postbiotics." This end product contributes to gut health and a stronger immune system.
"Fibre is a good example of something we don’t absorb, but that’s essential for our health,” says Rob, adding that “there is also a strong link between fibre and a reduced risk of chronic diseases like type 2 diabetes, heart disease, and even some cancers (colorectal cancer especially from consuming fibre from wholegrains).”
They could be harmless, but they could also be red flags.
Soluble vs insoluble fibre
There are two main types of fibre:
1. Soluble fibre: This type of fibre dissolves in water and forms a gel in the digestive tract. “It slows digestion, which helps you feel fuller for longer, and keeps blood sugar levels stable,” says Rob. “It also binds to cholesterol in the digestive system, helping to lower LDL (bad) cholesterol, and is an important ‘food’ source for your beneficial gut bacteria.” Oats, apples, beans and chia seeds are good sources of soluble fibre, he notes.
2. Insoluble fibre: “This type of fibre doesn't dissolve in water so, instead, it adds bulk to stool and helps move waste through the digestive system,” says Rob. "You’ll find it in wholegrains, nuts, seeds and the skins of fruits and vegetables."
The amount of soluble and insoluble fibre varies depending on whether you're eating a fruit, vegetable or whole grain but most high-fibre plant foods contain both.
How much fibre should you eat per day?
Adults want to aim for a minimum of 30g of fibre per day. “But most of us in the UK fall well short," says Rob. “The average intake is about 20g and only 6% of women and 12% of men reach the 30g target.”
So is there a single best time of day to eat fibre to reap its benefits? Rob says, “no”, but what is key is spreading your intake throughout the day.
“A lot of people get a fibre overload at one meal, like a big salad or a bran-heavy breakfast, and then nothing later on,” he notes. "That can lead to bloating or discomfort. Including fibre at every meal — say oats in the morning, lentils or veg at lunch, and wholegrains or beans at dinner — is more beneficial overall for digestion, energy levels and blood sugar balance.”
Signs that you're not getting enough fibre:
“Fibre adds bulk to your stool and that helps to retain water, which keeps everything moving through your digestive system,” says Rob. "Without enough fibre, the stool becomes hard and dry, which makes it harder to pass." Cue your digestive process slows down, which can lead to constipation.
Just remember that you need to drink plenty of water if you're also eating fibre-rich foods. Otherwise, you could become even more backed up.
If you get to the end of a meal and still feel hungry, or you crave something sweet after a big dinner, Rhian says it may be because the meal lacked fibre.
Eating a meal high in fibre helps to prevent hunger pangs for several reasons. Firstly, meals that are low in fibre digest rapidly so you often feel peckish soon after eating them. But when your meal is high in fibre, your stomach empties at a slower rate because fibre takes time to digest.
“Fibre-rich foods also take longer to chew, keeping us satisfied for longer periods,” Rhian says. “On the flip side, not getting enough fibre may lead to greater peaks and troughs in blood sugar, and therefore more cravings and impaired hunger signalling.”
These blood sugar spikes and crashes can also leave you feel tired and groggy. Fibre basically helps to balance blood sugar levels. “Specifically, soluble fibre, abundant in foods like oats, beans, lentils, apples and citrus fruits, can act as a brake on carbohydrate absorption, leading to a more gradual rise in blood glucose,” says Rhian.
Without the steadying effect fibre has on slowing digestion and sugar absorption, you may find you have more pronounced energy levels spikes and dips after meals, adds Rob.
“If your diet is low in fibre then you may also be missing out on essential nutrients linked to energy metabolism and the production of healthy red blood cells that carry oxygen around your body," he continues. "These include iron, magnesium and B vitamins.”
Rob namechecks beans, pulses and lentils as being especially important if you're vegetarian or vegan as they're rich sources of iron, which are key to energy production.
Magnesium isn't just good at night.
Dips in our blood sugar levels can also affect our mood by making us feel grumpy and anxious. The obvious reason for this is the exhaustion outlined above. But there is also a growing body of research into the gut-brain connection – and the relationship between gut health and mental health.
There is growing evidence that signals pass both ways between your digestive system and central nervous system, and the health of one affects the other. “Low fibre could be one piece of the puzzle,” says Rob, “especially if your overall diet is lacking in vegetables, fruits and wholegrains.”
This is because fibre feeds the beneficial bacteria in your gut – and these help to produce many of the chemical neurotransmitters that convey messages between your gut and brain. "A low-fibre diet may also lead to an imbalance in gut bacteria (dysbiosis), which some studies show can be associated with symptoms of low mood or anxiety."
But Rob cautions against thinking that eating more fibre will automatically boost your production of seratonin – the body's feel-good chemical. “While it’s true that around 90% of the body’s serotonin is produced in the gut, it’s mainly used locally in the gut rather than directly influencing mood,” he says. “Sleep, stress and hormones, all affect our mood, too.”
Inflammation is a major trigger for several diseases, including heart disease, type 2 diabetes and certain cancers. Not eating enough fibre may increase inflammation and the likelihood of developing these chronic diseases.
Our gut barrier is basically protected by a mucous layer. “This serves as our first line of defence against anything harmful,” Rhian says. “But when we don't eat enough fibre, we starve the trillions of bacteria and fungi that live in our gut and they can then start to feed on this protective mucous lining. So the less fibre we eat, the thinner our mucous membrane, and the higher our levels of inflammation.”
It's also worth remembering that 70% of your immune system is in the gut, so your diet can affect it. By eating your RDA of fibre, you fuel the good bacteria in your gut, which can help to fight inflammation and keep infections at bay.
And if you need extra support, try Artah's GI Fix or Thorne GI Relief – daily supplements that support this mucous layer in your gut.
As well as a gut-brain axis, there is also such a thing as the gut-skin axis – a.k.a the relationship between the health of our gut and the condition of our skin.
"The science is still evolving here, but growing evidence does show a strong connection between gut health and skin health," says Rob. Some studies have already linked psoriasis with inflammatory bowel disease, and dermatitis and rosacea with celiac disease, another common gut condition.
While a lack of fibre isn’t a direct cause of breakouts – and eating fibre-rich foods isn't the answer to clearer skin on its own – upping your intake may help "as part of a wider picture involving inflammation, gut health and diet quality,” says Rob. “When fibre intake is low, the balance of gut bacteria can shift, which has been linked to increased inflammation, a known contributor to skin conditions like acne and eczema.”
How to get more fibre – quick hacks
Given most of us aren't eating enough fibre each day, it's not exactly surprising that the trend for ‘fibremaxxing’ is taking off right now. Designed to strategically boost the amount of fibre in your meals, it's about pimping your favourite dishes and snacks with more fibre throughout the day to ensure that you're getting enough.
“Remember, ultra-processed foods are naturally quite devoid of fibre,” Rhian notes, but adding certain plant-based foods to your diet can pack in a large amount of fibre.
With that in mind, these are some simple ways you can up your fibre intake:
- Include beans and lentils often. “One cup of cooked beans or lentils can have up to 16g of fibre," says Rhian.
- If you're a cereal lover, choose a wholewheat option like Weetabix or porridge oats.
- Choose wholegrains. Go for wholemeal bread and wholewheat pasta.
- Eat more fruits and vegetables. “Try to eat them with their skins on for added fibre,” says Rhian. A good option is a baked potato with the skin on.
- Add fibre-rich toppings to dishes. “Nuts, seeds, goji berries and cacao nibs are excellent additions to porridge, smoothies, and salads," says Rhian. "You can also add seeds (flaxseed, sunflower, pumpkin) to salads, soups and stir fries.”
- Make your own chia pudding. 2 1/2 tablespoons of chia provides just under 10g of fibre. Combine the chia seeds with milk (cow or plant-based) in a jar or bowl. Add your sweetener of choice or a dash of vanilla, cover and chill overnight.
For more from Fiona Embleton, GLAMOUR's Associate Beauty Director, follow her on @fiembleton.
