When it comes to gut and digestive health, you’ve probably heard about the numerous benefits that fibre can offer.

Found in plant-based foods like legumes, nuts, seeds, grains as well as fruits and veggies (of course), ensuring there’s enough fibre in your diet can help prevent constipation, support digestive function and aid in weight management, as well as a whole list of other health benefits.

But how much fibre should you be eating per day and is there such a thing as too much? Keep reading below to find out!

Fibre is a type of carbohydrate found in plant-based foods that the human body is unable to break down, digest or absorb [1]. There are two main types of dietary fibre:

• Soluble fibre, which can be dissolved in water to form a gel-like substance in the digestive tract helps you feel fuller for longer. This type of fibre is found in oats, barley, legumes, fruits and certain vegetables.
  
  

• Insoluble fibre, which, as the name suggests, is unable to be dissolved in water. This type of fibre helps by adding bulk to stool, regulating bowel movements and avoiding constipation. It is found in whole grains, nuts, seeds, fruit skins and certain vegetables.

The recommended amount of fibre to consume tends to vary depending on age, but a minimum of 25 to 30 grams of dietary fibre per day is widely recommended for adults [2]. To achieve this target, it’s recommended to eat a variety of plant-based foods and increase consumption of fruit and vegetables.

Studies into global fibre intake have found that most people don’t consume enough fibre daily - one study estimated that most people need to increase it by around 50% [1]!

Some common signs that you aren’t consuming enough fibre include:

• Constipation and/or hard stool

Hard, dry stools that result in constipation often occur as the colon absorbs too much water. Soluble fibre aids in alleviating constipation by absorbing water as it moves through the digestive tract, which makes stool softer and easier to pass, while insoluble fibre helps move food through the digestive tract. Eating too little fibre may result in infrequent bowel movements or smaller, harder stools that are more difficult to pass.

• Feeling hungry even after meals

Soluble fibre slows the digestive process, which in turn slows down the rate at which your stomach empties to send a signal to your brain that translates into feelings of hunger, prompting you to eat again. Low-fibre meals tend to be digested quicker, which can leave you feeling hungry soon after eating.

• Fatigue/low energy

High-fibre foods provide a steady energy source for the body throughout the day, preventing spikes or crashes in blood sugar levels. Fluctuations in energy levels or feelings of fatigue can be due to unstable blood sugar and could be a sign you’re consuming an insufficient amount of fibre.

If you experience bowel incontinence, it’s important to consume enough fibre to keep your bowels healthy and regular, and to avoid any constipation which can exacerbate symptoms. A 2014 US study on individuals with faecal incontinence even found that those given a fibre supplement had a decrease of 51% in the frequency of soiling incidents [3].

While studies have found the majority of people consume too little fibre, it might surprise you to know that it’s also possible to consume too much fibre.

Overconsumption of fibre has its own set of symptoms, and some common signs you might be eating too much fibre include:

• Bloating and excess gas
  
  As we mentioned earlier, fibre is the part of edible plants that is unable to be digested by the human body. However, the bacteria in our colon are able to digest it and a by-product of this is the production of gas. Eating a lot of fibre means there is more available for the bacteria to break down, resulting in more gas than usual and contributing to feeling bloated [4].
  
  

• Abdominal discomfort
  
  As well as discomfort from bloating, eating too much fibre can result in other gastrointestinal discomfort such as cramping.
  
  

• Diarrhoea or Constipation

Insoluble fibre helps move food through the digestive process, and as it does so, it can also draw water into the digestive tract from outside of the intestine to help its journey along. These two forces combined can cause loose stools or diarrhoea.

On the other hand, eating too much fibre without consuming enough water can cause or worsen constipation.

While the above symptoms can be signs of too much or too little fibre, in some cases they may also indicate an underlying condition or even a deficiency - so it’s recommended to check in with your GP or treating healthcare professional before making any changes to your diet.

Similarly, if you suspect you’re experiencing any adverse effects of consuming either too much or too little fibre, we recommend discussing it with a healthcare professional or a registered dietician for advice and guidance tailored to your unique situation.

If you’ve been advised to increase your daily amount of fibre, it’s important to do so gradually and to stay adequately hydrated while doing so to allow your digestive system to adapt.