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:
1. You’re constipated
“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.
2. You get hungry soon after eating
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.”
3. You constantly feel tired
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.
4. You struggle with mood swings
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.