Fibre — or roughage as many of us know it — is a type of carbohydrate found in plant-based foods.
Despite the human body’s inability to actually digest fibre, it’s very important that we ingest it as it provides many health benefits. This includes everything from improved digestion to heart health and weight management.
So, how much fibre is a healthy dose, and are there any implications if we consume beyond the recommended amount?
To find out, Metro consulted Dr Barbara Kubicka, doctor and ex-NHS GP, to give us the low-down on what actually happens to the body when we eat too much fibre. Heads up, some of them are not pretty.
How much fibre should adults be eating per day?
‘In general, adults in the UK should aim for around 30 grams of fibre a day,’ says Dr Kubicka. Ideally, this should be from a mix of vegetables, fruit, whole grains, beans, nuts and seeds.
The key is building up your intake gradually and making sure you’re drinking enough water.
Dr Kubicka says: ‘When fibre intake jumps up too quickly, that’s usually when people start to experience these kinds of digestive symptoms.’
Why is fibre important for our diets?
‘Fibre is incredibly important for digestive health, and most of us in the UK don’t actually get enough of it,’ explains Dr Kubicka.
‘It supports the gut microbiome, helps regulate blood sugar and keeps the digestive system moving properly.’
But as with most things in nutrition, it’s possible to have too much of a good thing, particularly if someone suddenly increases their fibre intake quite quickly.
‘When that happens, the gut can struggle to adapt, and it’s common to see a few digestive symptoms appear,’ the doctor adds. Here, Dr Kubicka talks us through the five most common issues.
Bloating
According to Dr Kubicka, one of the first things people tend to notice when they consume too much fibre is bloating.
She explains: ‘If you suddenly increase fibre, particularly from whole grains, beans or supplements, the bacteria in the gut have a lot more to ferment.’
That process then produces gas, which can leave people feeling uncomfortably full or swollen after meals.
Passing wind
Alongside bloating, people often notice they’re passing more wind than usual.
While a little increase is completely normal when you improve your diet, if it becomes excessive, it’s usually a sign your digestive system is trying to catch up with the sudden change.
Stomach cramps
Dr Kubicka explains that some people may also experience stomach cramps or general digestive discomfort.
‘Insoluble fibre, which you find in foods like bran or certain whole grains, can stimulate the bowel quite strongly,’ she notes.
Therefore, if the body isn’t used to it, that extra stimulation can sometimes lead to cramping.
Constipation
‘Too much fibre can also have the opposite effect,’ the doctor adds. Meaning constipation.
Fibre adds bulk to stools and absorbs water, so if someone increases fibre without drinking enough fluid alongside it, it can actually make stools harder and more difficult to pass.
Looser stools
OK, there’s lots of bathroom talk here, but Dr Kubicka needs you to know the facts.
While some will experience the above, from cramping to constipation, for others digestion can go the other way and become a little too fast.
The doctor explains that a very high fibre intake can speed things up in the gut, which may lead to looser stools or more frequent trips to the bathroom.
Finally, the effects of too much fibre could be something as simple as the digestive system becoming very noisy.
‘If someone notices their stomach constantly rumbling or gurgling, it can be a sign that a lot of fibre is fermenting in the gut and producing gas.’
