Why Fibre Isn't The Whole Story

Jul 3
6 min read

Many people have heard the same advice at some point: “Eat more fibre.”

Whether the concern is constipation, bloating or digestive discomfort, increasing fibre is often one of the first recommendations people receive. The advice is usually well intentioned and, in many cases, entirely appropriate.

The problem is that most people are never told what it actually means. How much fibre should we aim for each day? Which everyday foods are genuinely high in fibre? Is a serving of vegetables enough? What is the difference between fibre, prebiotics and probiotics? Do foods such as tempeh, miso and yoghurt do the same job as beans and wholegrains? These terms are often used together, but they are not interchangeable. Each supports our digestive system in a different way.

Understanding these differences helps us build meals more intentionally rather than assuming every serving of vegetables contributes equally to our digestive health.

Three Different Jobs, One Healthy Gut

One reason digestive health can feel confusing is that terms such as fibre, prebiotics and probiotics are often used interchangeably. They are related, but they are not the same thing. Each performs a different role in supporting a healthy digestive system.

Dietary fibre is the indigestible part of plant foods. It adds bulk to our stools, supports regular bowel movements and helps us feel fuller for longer. Certain types of fibre can also help regulate blood sugar levels and support healthy cholesterol.

Prebiotics are specific types of fibre that nourish the beneficial bacteria already living in our intestines. Rather than acting directly on our digestive system, they provide food for our gut microbiome, helping these bacteria grow and thrive.

Probiotics, on the other hand, are the beneficial microorganisms themselves. They are naturally found in fermented foods such as yoghurt, tempeh and miso, and are also available as supplements. Their role is different from fibre. They contribute beneficial bacteria, while prebiotics help feed them.

Although each has its own function, they work best together. Eating probiotic foods without enough fibre is a little like planting a garden without watering it. Likewise, eating plenty of fibre while neglecting hydration or physical activity may not produce the digestive benefits we expect.

Good digestive health is rarely built around one “superfood” or supplement.

Not All Fibre Is Created Equal

This is where many misconceptions begin.

Someone may proudly say they eat vegetables every day, yet still fall well short of their recommended fibre intake. Another may assume that all vegetables contain similar amounts of fibre, when in reality the differences can be surprisingly large.

For example, a cup of raw spinach contains relatively little fibre despite being rich in vitamins and minerals. By comparison, foods such as guava, chickpeas, red beans, green beans, edamame and black fungus contribute substantially more fibre per serving.

This does not make spinach unhealthy. It simply reminds us that different foods contribute different nutritional benefits. Some are valued for their vitamins. Others for hydration. Others for protein. Fibre is only one part of the picture.

Where Can We Actually Find Them?

Understanding the differences between fibre, prebiotics and probiotics is one thing. Knowing where to find them is another.

The good news is that many of these foods are already sitting on supermarket shelves or appearing regularly on Singapore dining tables. The challenge is recognising what each contributes.

FOOD	FIBRE	PREBIOTIC	PROBIOTIC	NOTES
Guava	⭐⭐⭐⭐⭐	⭐	❌	One of the highest-fibre fruits commonly available.
Edamame	⭐⭐⭐⭐	⭐⭐	❌	Excellent source of both fibre and protein.
Chickpeas	⭐⭐⭐⭐⭐	⭐⭐	❌	High in fibre and versatile for salads, curries or hummus.
Red beans (Adzuki)	⭐⭐⭐⭐	⭐⭐	❌	A familiar ingredient in both savoury dishes and desserts.
Green beans (Mung beans)	⭐⭐⭐⭐	⭐⭐	❌	Rich in fibre and commonly used in soups and desserts.
Black fungus (木耳)	⭐⭐⭐⭐	⭐⭐	❌	An underrated source of dietary fibre.
Barley	⭐⭐⭐	⭐⭐⭐	❌	Provides soluble fibre and is commonly used in soups and drinks.
Kai lan / Chye sim	⭐⭐⭐	⭐⭐	❌	Good everyday vegetables that contribute useful fibre.
Broccoli	⭐⭐⭐⭐	⭐⭐	❌	One of the higher-fibre vegetables.
Banana	⭐⭐	⭐⭐⭐	❌	Especially when slightly green, it provides useful prebiotics.
Garlic & onions	⭐	⭐⭐⭐⭐⭐	❌	Excellent natural prebiotic foods.
Tempeh	⭐⭐⭐	⭐⭐	⭐⭐⭐⭐	Fermented soybeans provide fibre, protein and beneficial bacteria.
Miso	⭐	⭐	⭐⭐⭐⭐	Fermented, but best enjoyed in moderation because of its sodium content.
Mui choy / Suan cai	⭐	⭐	⭐⭐⭐	Traditional fermented vegetables, also relatively high in sodium.
Plain yoghurt (live cultures)	⭐	⭐	⭐⭐⭐⭐	Excellent probiotic food, but contributes very little fibre.
Wakame / dried seaweed	⭐⭐	⭐⭐	❌	Adds fibre and minerals to soups.
White fungus (雪耳)	⭐⭐	⭐⭐	❌	Contains useful polysaccharides but is not a major fibre source.
Wintermelon / Old cucumber	⭐	⭐	❌	Nutritious and hydrating, but not significant sources of fibre.

One pattern quickly becomes apparent: very few foods provide everything.

Most contribute in one or two areas, which is why digestive health is rarely built around a single “superfood”. A varied diet almost always outperforms searching for one perfect ingredient.

How Much Fibre Do We Actually Need?

For most healthy adults, the recommended daily intake is surprisingly achievable.

Women aged 19 to 50: about 25 grams per day
Men aged 19 to 50: about 38 grams per day
Adults over 50: recommendations decrease slightly because calorie requirements generally fall with age, but most people still benefit from aiming for around 21 to 30 grams each day.

Many adults consume considerably less fibre than these recommendations. One reason is that fibre is easy to overestimate. A meal may contain vegetables, yet still contribute only a few grams of fibre. Simply adding one serving of greens to lunch does not necessarily mean we are meeting our daily needs.

A more useful question is not whether we ate vegetables today. It is whether we consumed enough fibre across the entire day.

What Does Meeting Your Daily Fibre Target Look Like?

For many people, recommended fibre intake is just another number.

In practice, it could look something like this:

MEAL	EXAMPLE	APPROX. FIBRE
Breakfast	Two slices wholemeal toast with peanut butter, one apple (with skin)	~10 g
Lunch	Yong tau foo with leafy greens, black fungus, mushrooms, dried seaweed, beancurd skin, tofu and one small bowl of brown rice	~ 8 – 9 g
Snack	One guava	~ 8 – 9 g
Dinner	Steamed chicken with stir-fried kai lan	~ 5 – 6 g
Approximate daily fibre intake: 31 – 34 grams. Fibre values are approximate and will vary depending on portion sizes and brands.

The point is not to follow this menu exactly. It simply illustrates that the recommended fibre intake can often be achieved through familiar foods and small choices made consistently throughout the day.

Should We Take A Supplement?

Once people learn that they are not meeting their fibre requirements, the next question often follows naturally: should I take a fibre supplement instead? For most people, food should remain the starting point. Whole foods provide not only fibre, but also vitamins, minerals and countless other nutrients that work together to support overall health. They also make meals more satisfying and enjoyable.

That said, supplements can have a role. Psyllium husk is one of the most well-studied fibre supplements and can be particularly helpful for people who struggle to consume enough fibre through food alone. It is rich in soluble fibre and may help support bowel regularity while also contributing to healthier cholesterol and blood sugar levels. Chia seeds offer another convenient option. Although not a replacement for a varied diet, they provide fibre, healthy fats and can be easily added to yoghurt, oatmeal or smoothies.

Supplements, however, are exactly what their name suggests. They are intended to supplement, not replace, a balanced diet. For people who already eat a varied, fibre-rich diet, they may add little benefit. They are generally most useful when dietary intake remains insufficient or when recommended by a healthcare professional.

Fibre Is Only Part Of The Story

Increasing fibre is not always enough on its own. Our digestive system also depends on adequate hydration and regular movement. Fibre absorbs water as it moves through the digestive tract. Without enough fluid, increasing fibre can sometimes make constipation worse rather than better.

Physical activity also plays an important role. Something as simple as a daily walk helps stimulate normal bowel movement and supports healthy digestion. This is one reason digestive health is influenced not only by what we eat, but also by how we live.

Looking after our gut is rarely about changing one thing. It is about allowing several good habits to work together. At the same time, persistent changes in bowel habits, blood in the stool, unexplained weight loss or ongoing abdominal pain should not be attributed to fibre alone and deserve medical assessment.

Small Choices, Lasting Benefits

Digestive health is often discussed in terms of miracle foods, expensive supplements or the latest wellness trend. The reality is usually much simpler.

Most of us do not need a complete overhaul of our diet. We benefit far more from understanding the role different foods play and making small, sustainable adjustments over time. Adding another serving of vegetables. Choosing beans or edamame more often. Including fermented foods as part of a balanced diet. Drinking enough water. Staying physically active.

None of these changes is particularly dramatic on its own. Together, however, they create the conditions that allow our digestive system to function well for years to come.

The most helpful question is no longer, “What should I eat more of?” It is, “Am I giving my digestive system everything it needs to do its job well?” Good digestive health is rarely built around one perfect food or one remarkable supplement. It is built through many thoughtful choices, repeated consistently over time.