Fibre is probably one of the most overlooked nutrients in our diets. Yet research persistently shows that following a fibre-rich diet is linked to a number of important health benefits. You probably already know that “roughage keeps you regular”, but did you also know that it plays a crucial role in promoting gut health, immune function, blood sugar balance and heart health?
Adults should aim for 30g of dietary fibre a day, according to the NHS, but BANT-registered nutritionist Charlotte Faure Green (@charlottefauregreennutrition) says most people aren’t regularly consuming anywhere near that. “The latest National Diet and Nutrition Survey showed the average UK intake is 17.2g per day for women and 20.1g per day for men.
“In today’s Western society, the taste for whole foods, naturally rich in fibre, has swung toward hyper-palatable, ultra-processed convenience foods (UPFs) which sit lower on the fibre scale,” she says. UPFs typically have much of their natural fibre stripped during processing.
What exactly is fibre and why is it so beneficial?
“Fibre is a type of carbohydrate found in plant foods that isn’t absorbed by humans, so it reaches the large intestine intact,” explains Faure Green.
There are two main types of fibre – soluble and insoluble – the former dissolves in water, forming a gel-like substance in the gut, while the latter doesn’t dissolve in water. But rather than “getting bogged down” with the different terms, she stresses it’s more important to concentrate on hitting a variety of fibre-rich foods per day – fruit and vegetables, whole grains, nuts and seeds, beans, and legumes – “as there’s plenty of crossover in terms of benefits between the types.”
Fibre is vital for healthy digestion. “It adds bulk to our stool, making us more “regular” and feeds our microbiome – the diverse community of bacteria, fungi and yeasts that lives in our digestive tract,” she continues.
The benefits of a thriving microbiome don’t stop at the gut, she adds. “Studies show that a diet rich in fibre may reduce the risk of developing Type 2 diabetes, heart disease, and depression. Research suggests that positive alterations in the gut microbiota can affect brain neurochemistry, improving mood, emotional regulation, and our stress response.”
Hannah Alderson, nutritionist and hormone specialist, adds that eating enough fibre can also have a positive impact on your hormones. “It can help with blood sugar regulation and get you ‘moving,’ all of which will support a better environment for hormone balance, as it supports detoxification, your microflora and insulin sensitivity. This is important for anyone with PCOS, PMS or during pregnancy, postnatally, perimenopause or menopause.”
So what happens to the body if we don’t get enough fibre? “A diet that is low in fibre is linked to both looser stools and constipation and is shown to increase the likelihood of developing gastrointestinal conditions and bowel cancer,” Faure Green says.
Day-to-day symptoms of insufficient fibre intake may include either going to the bathroom too frequently or not enough. “You may find that you have big blood sugar spikes, followed by a crash – this blood sugar rollercoaster can have an impact upon your energy levels, sleep, and mood.
“You might find that you’re always hungry – high-fibre foods tend to be whole foods with a solid profile of vitamins and nutrients that fill you up and keep you sated for longer – or you may find you catch every cold going – dietary fibre supports the gut-associated lymphoid tissue, a huge component of your immune system. In short, if you’re not getting enough fibre, you’re unlikely to be feeling your best self.”
Here are some easy ways to pack more fibre into your diet.
Keep skins on fruit and veg
Leave the fibrous skin on your fruit and veg as much as possible, advises Faure Green, particularly with carrots, potatoes, courgettes, apples, pears, and cucumber. “Peeling these might reduce the fibre in your food by up to a third.”
Alderson adds that, for this reason, it can be beneficial to shop organic for these items, “just be sure to give them a good wash.” “For example, the fuzzy skin on kiwis is absolutely edible – cutting it into thinly sliced medallions can make it more appealing and increase its fibre content by up to 50 per cent. One skin-on green kiwi is equivalent to about 3.5g of fibre,” she says. “Similarly, if you’re adding strawberries to a smoothie, simply leave their little green top hats on.”
Eat more potatoes
“Potatoes get a bad rep that they just don’t deserve, they are one of the healthiest foods going – our brain needs carbohydrates to function – both sweet and white contain high levels of fibre, and other nutrients including magnesium and vitamin C,” says Faure Green. For context, a baked jacket potato with the skin on contains around 4.7g of fibre.
“To up the health benefits further, allow your potatoes to cool in the fridge once cooked before eating. This creates a specific type of fibre called resistant starch which is too durable to be broken down by our digestive enzymes, meaning very little of the sugars reach our bloodstream – rather it travels down to the colon where our gut bacteria utilise it to make health-promoting short-chain fatty acids, B vitamins, amino acids, all without the blood sugar spike that might accompany enjoying our carbs.”
Choose brown carbs over white
Opting for whole grains like brown rice, wholewheat pasta, bulgur wheat and spelt over refined (usually white) grains is an easy win. As is choosing wholemeal, granary, seeded or rye bread over white. A meta-analysis of 45 studies found that eating more whole grains is associated with a reduced risk of heart disease, cancers and diabetes.
Pick smoothies over juices
“Smoothies use whole fruit and vegetables, meaning they’re packed with fibre, while juicing removes the fibre as pulp,” Faure Green says. It’s also easy to add in more fibre sources to them, such as nuts, seeds and oats, to increase their nutritional value – the bonus being they’ll fill you up for longer.
Stock the store cupboard
The easiest way to up your fibre intake with minimal effort is by adding sources to meals and snacks where you can. “Have seeds to hand to sprinkle over salads, breakfast bowls and scrambled eggs – I like to have chia, flax, and pumpkin seeds within reach for a quick fibre-boost to any meal,” says Faure Green. “Similarly with beans – having a tin of plain beans (think borlotti, cannellini or chickpeas) makes a quick addition to any soup, salad or stew.”
Stock up on rolled jumbo oats and add handfuls to smoothies or yoghurt for an added dose of fibre, suggests Alderson. “Just remember to add in sources of protein and fat to keep your blood sugar on point.”
Use your freezer
“Most of us are guilty of throwing out a bag of spinach after an extended stint in the fridge. Having a variety of frozen vegetables (and fruit) means that we have no excuses when it comes to putting together a nutritious meal with a good fibre component. It’s cheaper too. For example, peas are a fibre powerhouse, and arguably, go with most meals,” Faure Green adds.
