The Importance of Dietary Fibre

Dietary fibre is the indigestible part of plant foods, such as fruit, vegetables, grains, nuts, seeds and legumes. Fibre adds bulk to our stools, promotes the growth of healthy bacteria in our bowel, and also acts a sponge, absorbing fluid to soften the stools.

There are two types of dietary fibre: soluble and insoluble fibre. Insoluble fibre adds bulk to our stools by absorbing water and is found in nuts, grains, seeds, and the skin of fruit and vegetables. Soluble fibre forms a thick gel that softens the stool, and is found in oats, legumes, and some fruit and vegetables.

The Recommended Daily Intake (RDI) of fibre for those aged over 65 years is 25-30g. Fibre is important for maintaining a healthy gut and reducing the risk of constipation. Constipation can be described as the infrequent passing or small or hard stools, which may involve straining, and unfortunately is a commonly reported problem in Residential Aged Care Facilities (RACF). Constipation can lead to a feeling of discomfort, and also fullness, which can impact appetite and oral intake.

Factors that may contribute to constipation in RACF include:

  • Medications (particularly those used for controlling pain)
  • Reduced physical activity
  • Irregular or poor oral intake
  • Relying on assistance to go to the bathroom
  • Delayed urge to open bowels due to lack of privacy
  • Poor fibre intake
  • Inadequate fluid intake
  • Poor menu choices
  • Texture modified diets, such as puree diets (low in insoluble fibre)
  • Poor dentition, leading to avoidance of fibrous fruit and vegetables

In order to prevent constipation, it is vital that the menu offered to residents contains adequate amounts of fibre and that high fibre options are available for residents who require them. Implementing high fibre menu options can also reduce costs spent on the use of aperients and enemas for residents.

The differences between low and high fibre options are displayed in the table below:

Low Fibre Option Fibre (g) High Fibre Option Fibre (g)
Cornflakes (1 cup) 1g Weet Bix (2 biscuits) 3.5g
White bread (2 slices) 1.8g High fibre white bread (2 slices) 5.6g
White flour (100g) 3.6g Wholemeal flour 8.8g
Milk arrowroot biscuit 0.5g Muffin with dried fruit 4g

Simple substitutions that can be made in RACF to increase residents’ fibre intake include:

  • Swapping white bread for wholemeal or high fibre white options
  • Offering wholegrain breakfast cereals, such as All Bran, Muesli, Porridge or Weet Bix
  • Offering wholemeal or shredded wheat biscuits in place of plain biscuits
  • Adding dried or fresh fruit to cakes, biscuits and desserts where possible
  • Adding lentils and beans to casserole dishes and soups

Furthermore, to allow fibre to work effectively, adequate fluid intake is essential. For tips on helping residents to meet their fluid requirements, please refer to our article on Hydration in Aged Care.

In summary, there are many ways to modify the food provided to residents to assist with meeting fibre requirements and reducing constipation. For more information regarding increasing the fibre content of your menu or to arrange education for care and catering staff, please speak with your Dietitian from the Eat Well Nutrition team.


Bartl R and Bunney C (2015) Best Practice Food and Nutrition Manual for Aged Care Edition 2. Gosford, Central Coast Local Health District.