Key Takeaways

• Soluble fibre dissolves in water and forms a gel-like substance that may help regulate blood sugar, support heart health, and improve digestion.
• Insoluble fibre does not dissolve in water and helps promote regular bowel movements by adding bulk to stool.
• Most plant-based foods contain a combination of both types of fibre.
• Adults should aim for approximately 22–34 grams of fibre daily, depending on age and sex.
• Eating a variety of fruits, vegetables, legumes, nuts, seeds, and whole grains is the easiest way to get enough fibre.

What Is Fibre?

Fibre is a type of carbohydrate found in plant foods that the body cannot fully digest. Unlike other carbohydrates that are broken down into sugar and absorbed into the bloodstream, fibre passes through much of the digestive system largely intact.

Although it isn’t digested, fibre plays a vital role in overall health. It supports digestion, helps regulate blood sugar, promotes healthy cholesterol levels, and may reduce the risk of several chronic diseases.

There are two primary types of dietary fibre:

Soluble Fiber

Soluble fibre dissolves in water and forms a gel-like substance in the digestive tract. This slows digestion and can help control blood sugar and cholesterol levels.

Insoluble Fiber

Insoluble fibre does not dissolve in water. Instead, it adds bulk to stool and helps food move more efficiently through the digestive system.

Most plant foods contain both types, although some foods provide higher amounts of one than the other.

Benefits of Dietary Fibre

A diet rich in fibre has been associated with numerous health benefits, including:

• Supporting digestive health
• Promoting regular bowel movements
• Helping regulate blood sugar levels
• Lowering LDL (“bad”) cholesterol
• Supporting healthy weight management
• Increasing feelings of fullness
• Reducing inflammation
• Supporting heart health
• Potentially lowering the risk of certain cancers, including colorectal cancer

Benefits of Soluble Fibre

Soluble fibre is particularly known for its ability to absorb water and form a gel. This process may help:

Improve Blood Sugar Control

By slowing digestion, soluble fibre can reduce rapid spikes in blood glucose after meals. This can be particularly beneficial for people with insulin resistance or diabetes.

Lower Cholesterol Levels

Soluble fibre binds with cholesterol-containing compounds in the digestive tract, helping remove them from the body and potentially lowering LDL cholesterol.

Help Manage Diarrhoea

Because it absorbs water and adds consistency to stool, soluble fibre may help improve loose stools and diarrhoea.

Increase Fullness

The gel-forming effect of soluble fibre slows stomach emptying and may help control appetite.

Benefits of Insoluble Fibre

Insoluble fibre acts differently within the digestive tract.

Supports Regular Bowel Movements

By adding bulk to stool, insoluble fibre helps move waste through the intestines more efficiently.

Helps Prevent Constipation

Insoluble fibre attracts water into stool, making it easier to pass and reducing straining during bowel movements.

Supports Digestive Health

A healthy digestive system depends on regular movement through the gut. Insoluble fibre helps maintain this process and may contribute to long-term bowel health.

Soluble vs. Insoluble Fibre: Which Is Better?

Neither type is better than the other. They simply provide different benefits.

Health Goal	Soluble Fiber	Insoluble Fiber
Relieve Diarrhea	✓✓	✓
Relieve Constipation	✓	✓✓
Lower Cholesterol	✓✓	✓
Improve Blood Sugar Control	✓✓	✓
Increase Fullness	✓✓	✓
Support Weight Management	✓✓	✓
Promote Regular Digestion	✓	✓✓

For optimal health, it’s best to consume a variety of foods that provide both types of fibre.

Best Sources of Soluble Fibre

Foods rich in soluble fibre include:

• Oats and oat bran
• Barley
• Apples
• Citrus fruits
• Bananas
• Pears
• Carrots
• Sweet potatoes
• Brussels sprouts
• Beans
• Lentils
• Chickpeas
• Psyllium husk

Best Sources of Insoluble Fibre

Foods rich in insoluble fibre include:

• Whole wheat
• Wheat bran
• Brown rice
• Quinoa
• Nuts
• Seeds
• Leafy greens
• Broccoli
• Cauliflower
• Fruit skins and vegetable peels

How Much Fibre Do You Need?

General daily recommendations suggest:

Group	Daily Fibre Target
Women	22–28 grams
Men	28–34 grams

Unfortunately, many adults consume far less than recommended. Increasing intake gradually can help prevent digestive discomfort while allowing the body to adapt.

Can You Eat Too Much Fibre?

While fibre is beneficial, suddenly increasing intake can sometimes lead to:

• Bloating
• Gas
• Abdominal discomfort
• Cramping
• Changes in bowel habits

These symptoms are more common when fibre intake increases rapidly or when adequate water intake is not maintained. Drinking plenty of fluids is essential when consuming a high-fibre diet.

People with certain digestive conditions, including active inflammatory bowel disease flare-ups, may need personalised guidance from a healthcare professional before significantly increasing fibre intake.

Frequently Asked Questions

Is soluble or insoluble fibre better?

Both are important. Soluble fibre supports cholesterol, blood sugar, and appetite regulation, while insoluble fibre helps maintain regular bowel movements and digestive health.

Which fibre helps with constipation?

Both can help, but insoluble fibre is particularly effective because it adds bulk to stool and promotes movement through the digestive tract.

Which fibre helps with diarrhoea?

Soluble fibre may help by absorbing excess water and improving stool consistency.

Do I need fibre supplements?

Whole foods should be your primary source of fibre. Supplements can be useful in certain situations but generally provide fewer nutritional benefits than fruits, vegetables, legumes, and whole grains.

Final Comments

Soluble and insoluble fibre each play unique roles in maintaining good health. Soluble fibre supports blood sugar control, cholesterol management, and digestive balance, while insoluble fibre promotes regular bowel movements and digestive efficiency.

Rather than focusing on one type over the other, aim to eat a wide range of plant-based foods every day. A varied diet rich in fruits, vegetables, legumes, nuts, seeds, and whole grains will naturally provide the balance of fibre your body needs to thrive.

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