When was the last time you thought about fibre?
If you’re like most people, probably not recently. Protein gets the glory, carbs get the blame, and fibre often gets forgotten. I was shocked to learn research shows that over 90% of adults don’t reach the recommended daily fiber intake!
Why the shortfall? Processed foods, low-veg diets, and the fear of carbs. Fibre is found in foods like whole grains, beans, fruits, and vegetables – foods that many modern diets push aside.
And here’s the catch: your body will tell you when it’s running low on fibre, just not always in obvious ways. Instead, the signs sneak up, through your digestion, your energy, even your long-term health.
Today, we will explore the five subtle signs of fibre deficiency backed by science, and why fixing this quiet gap in your diet could change more than just your digestion.
1. You’re Regularly Bloated or Constipated
We will start with the most familiar: irregular bowel movements. If you are struggling with constipation, straining, or feeling bloated after meals, it could be your gut crying out for fibre.
Fibre, especially the insoluble type found in whole grains, vegetables, and seeds, adds bulk to your stool and helps food move smoothly through your intestines. Without enough, waste slows down, causing discomfort.
One meta-analysis of over 900,000 people found that those who ate the most fibre had a 23% lower risk of death overall, but also significantly reduced risk of diseases related to poor digestion, like colorectal cancer (PMID: 25143474).
2. You feel full, but hungry again quickly
Ever had a big meal and then felt like snacking an hour later? That is often a sign your plate was missing fibre.
Fibre slows down digestion, keeping blood sugar steady and satiety hormones active. Without it, you burn through your meal fast, leading to cravings and energy dips.
A 2019 Lancet systematic review (185 studies + 58 clinical trials) showed that people who ate 25–29 g of fibre per day not only lowered their risk of heart disease and diabetes but also enjoyed improved satiety and healthier weight management (PMID: 30638909).
3. Your energy and mood swing easily
A 2021 meta-analysis of 18 studies found that each additional 5 grams of fibre per day was linked to a 5% lower risk of depression (PMID: 36692989). Adolescents who ate the most fibre had an impressive 57% lower risk of depressive symptoms compared to those who ate the least.
If you notice mood dips, brain fog, or energy slumps that don’t match your sleep or stress, your gut (and fibre intake) could be part of the story.
4. Your blood tests show rising blood sugar or cholesterol
Sometimes, the “silent” signs of low fibre show up in your lab work before you feel them.
Fibre binds cholesterol in the gut and slows sugar absorption. Without enough, cholesterol may creep higher and blood sugar may spike after meals.
A meta-analysis of 17 cohort studies (488,293 people) found that people with the highest fibre intake had a 19% lower risk of type 2 diabetes. Insoluble fibre (from whole grains, bran, vegetables) showed the strongest protection (PMID: 24389767).
Another meta-analysis found that every additional 10 g/day of fibre lowered the risk of dying from cardiovascular disease by 9% (PMID: 26711548).
5. You’re missing the glow: skin, hormones, and immune health
This one surprises many people. Low fibre can affect more than digestion and labs – it also influences hormones, skin, and immunity.
Fibre helps the body detoxify naturally by binding excess estrogen and waste products in the gut. Without it, hormones can recycle back into the bloodstream, potentially worsening PMS, acne, or inflammatory conditions.
Meanwhile, a healthy gut microbiome (fuelled by fibre) supports your immune system, with around 70% of immune cells residing in the gut (PMID: 36543697).
If your skin feels inflamed, your cycles are irregular, or your immune system seems weaker than usual, don’t overlook your fibre intake.
How much fibre do you actually need?
Here’s where things get clear:
Women should aim for 25–30 g/day.
Men should aim for 30–38 g/day.
The average intake in Western countries is barely 15 g/day. No wonder low fibre is now listed as a global dietary risk factor for premature death (Lancet, 2019).
Practical ways to boost fibre (without the bloat)
Start Slow – Add 5g at a time. Your gut bacteria need time to adapt.
Hydrate – Fibre works best with water.
Mix Sources – Get both soluble (oats, apples, beans) and insoluble (whole grains, seeds, veggies).
Think Whole – Swap white bread/pasta for wholemeal; snack on fruit instead of juice.
Lean on Plants – Legumes, nuts, seeds, and vegetables are your allies.
Final word: Your Body’s Quiet Signals
Low fibre doesn’t always shout but it whispers through bloating, cravings, mood shifts, blood tests, and even skin changes. The science is clear: meeting your daily fibre needs isn’t optional; it’s a foundation for long-term health.
Because the truth is simple: when you fuel your body with enough fibre, you are not just supporting digestion — you are protecting your heart, balancing your mood, and investing in a longer, healthier life.
Struggling to make sense of fibre and what your family really needs? My eBook The Forgotten Fibre breaks it all down into simple steps, with tips you can put into practice straight away.