Diet & Nutrition
   
 

Dietary Fibre and Your Body

Dietary fibre is the portion of food that cannot be digested by our bodies. Therefore, there is a misconception that dietary fibre is just food remains which provide no nutritional value. Actually, dietary fibre can be divided into two types: soluble and insoluble fibre. Both fibres serve different functions in the body and can be obtained from different foods.

The health benefits of dietary fibre

Eating moderate amount of dietary fibre-rich foods helps prevent the development of many chronic diseases and improve body health.

  • Prevent and relieve constipation
    Dietary fibre increases faecal volume and stimulates peristalsis. It swells, absorbs water and lubricates the large intestine to soften faeces and make defecation easier.

  • Help maintain gut health
    Dietary fibre promotes the activity of intestinal bacteria to maintain gut health.

  • Prevent colon cancer
    Dietary fibre shortens the retention time of food residues in the intestine and so prevents the accumulation of carcinogen.

  • Help weight-control and reduce the chance of obesity
    Eating dietary fibre-rich food requires relatively more time to chew. This can make people feel full easily and so eat less food.

  • Help stabilize of blood glucose level and control diabetes
    Soluble dietary fibre can slow down the absorption of blood glucose.

  • Help lower blood cholesterol level and prevent heart disease
    Soluble dietary fibre combines with bile to enhance bile excretion and lower blood cholesterol level.

Foods rich in dietary fibre

Examples:

Cereals - wholemeal bread, red rice, oatmeal
Vegetables - Chinese kale, broccoli, spinach
Root vegetables - potato, sweet potato
Beans - garbanzo beans, red kidney beans, soya beans, adzuki beans
Fungi - straw mushroom, shiitake, mushroom, snow fungus, cloud ear fungus
Fruits - orange, grapefruit, dried prune
Others- sesame, almond, cashew nut, peanut

Daily dietary fibre requirement

Adolescents and adults need not less than 25g of dietary fibre everyday while children need less. Add 5 to a child's age to calculate the amount of dietary fibre needed per day (Age + 5 = grams of dietary fibre required per day).
For example, a 6-year-old child would need 6+5=11g of dietary fibre per day.

Reference: Centre for Health Protection (Dietary Fibre)
https://www.chp.gov.hk/en/static/90018.html

Essential facts

  • Obtain dietary fibre from food rather than supplements (e.g. fibre tablets, powders, etc.).
  • Eat different varieties of dietary fibre-rich food as dietary fibre obtained from different food serves different functions.
  • Increase the intake of dietary fibre progressively to avoid gastrointestinal symptoms caused by a sudden intake of a large amount of dietary fibre.
  • Eat unpeeled fruits and vegetables (e.g. unpeeled cucumber, plums, apple and grapes, etc.).
  • Eating fresh fruit is better than drinking fruit juice because most of the dietary fibre in fruits is damaged when squeezing the juice.
  • Dietary fibre absorbs water. It is suggested to drink 6-8 glasses of fluid per day to allow the dietary fibre function effectively.
  • Although dietary fibre is important to health, we should not neglect other food groups. A balanced diet and regular exercise are of the utmost importance to good health.

Dietary fibre content of different food groups

Food group and amount Dietary fibre (g)
Grains
White rice (cooked) 100g 0.2
Brown rice (cooked) 100g 1.8
Wholemeal bread 100g 6.8
Wholegrain breakfast cereals 100g 11.7
Cornflakes 100g 3.6
Oatmeal (uncooked) 100g 10.6
Oatmeal (cooked) 100g 1.7
Quinoa (cooked) 100g 2.8
Fruits/ dried fruits
Apple (with skin) 100g 2.4
Orange (peeled and seedless) 100g 2.4
Banana (peeled) 100g 2.6
Green Kiwi 100g 3.0
Avocado 100g 6.7
Asian pear 100g 3.6
Dried Apricot 100g 7.7
Dried prune 100g 7.1
Raisin (seedless) 100g 3.7
Vegetables
Broccoli (cooked) 100g 3.3
Chinese kale (cooked) 100g 2.5
Spinach (cooked) 100g 2.4
Lettuce (cooked) 100g 1.9
Choy sum (cooked) 100g 1.6
Tomato (cooked) 100g 1.4
Carrot (cooked) 100g 3.0
Corn (cooked) 100g 2.4
Shiitake (cooked) 100g 2.1
Potatoes (baked, with skin) 100g 2.1
Sweet potato (baked, with skin) 100g 3.3
Dried beans
Garbanzo bean (cooked) 100g 7.6
Soya bean (cooked) 100g 6.0
Adzuki bean (cooked) 100g 7.3
Mung bean (cooked) 100g 7.6
Red kidney bean (cooked) 100g 7.4
Nuts
Cashew nut (roasted) 100g 3.0
Peanut (roasted) 100g 8.0
Sesame (roasted) 100g 14.0
Pistachio (roasted) 100g 10.3
Almond (roasted) 100g 11.8

An example of diet rich in dietary fibre

Meal Food type and amount Dietary fibre content (g)
Breakfast low-fat milk, 1 glass (240ml) 0
wholemeal bread, 2 slices (56g) 3.8
egg, 1 piece (50g) 0
Morning snack raisins, 1/3 cup (49g) 1.8
almond, 1oz. (28g) 3.3
Lunch brown rice, 1 bowl (195g) 3.5
steamed fish (120g) 0
broccoli (cooked), 1/2bowl (90g) 3.0
banana, 1 piece (118g) 3.0
Afternoon snack boiled corn 1/2 bowl (82g) 2.0
Dinner brown rice, 1 bowl (195g) 3.5
Chinese kale (cooked), 1/2 bowl (65g) 1.6
meat or chicken (120g) 0
orange,1 piece (131g) 3.1

  Total dietary fibre content 28.6
Reference:
Nutrient Information Inquiry System, Centre for food safety


(Revised in October 2018)

 

 
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Last Revision Date : 22 November 2018