A high fibre diet has been shown in many studies (1) to be linked to a reduced risk of cancers, heart disease, diabetes and obesity.

Recently published data (2) has found that a higher intake of dietary fibre may play a beneficial role in the prevention of body weight gain and gain in waist circumference measurement.  The authors of this study, published in the American Journal of Clinical Nutrition, looked at the association of dietary fibre with changes in weight and waist circumference.  The research involved over 89,000 individuals ages 20-78 who were free of cancer, cardiovascular disease, and diabetes at the beginning of the study.  The participants were followed for 6.5  years.  The results show (2) that a higher intake of total fibre was associated with a reduced likelihood of weight and waist circumference change when compared to low intake of total dietary fibre. 

Fibre may be having an impact on weight through various indirect methods.  Fibre is generally quite filling, it promotes satiety and hence decreases feelings of hunger – eating a fibre rich diet may therefore reduce daily calorie consumption.  In addition to this, foods which are high in fibre, such as vegetables and pulses/beans, tend to be bulky (high volume) and low in calorie content and have the added benefit of being packed with vitamins, minerals and bioflavonoids (bio-active plant chemicals)

Here in the UK the majority of adults are not meeting the recommended daily intakes of 18g of fibre.  The National Diet and Nutrition Survey (3) reported that 72% of men and 87% of women were not meeting the recommended 18g of NSP per day.  In 2000/2001, the average daily intake of fibre was 15.2g for men and 12.6g per day for women!  The recommended amount of 18g per day was set in 1991 and is lower than most of the recommended intakes elsewhere in the world.  Many health professionals would advocate a daily fibre intake of 25-35g daily.  A healthy balanced diet rich in whole grains, pulses, beans, lentils, fruit and vegetables is a great way of increasing intakes.

There are two types of fibre: insoluble fibre and soluble fibre.  Insoluble fibre cannot be digested by the body, it helps to promote fullness and also aids the removal of waste from the body.  Thus is keeps the bowels healthy and prevents against constipation.  Vegetables, fruits and wholegrains contain a lot of insoluble fibre.  Soluble fibre can be partially digested and may help to reduce the amount of cholesterol in the blood. Good sources of soluble fibre include oats and pulses such as beans and lentils.

In addition to the impact of fibre on satiety and potentially on weight, as mentioned above, low fibre intakes are associated with constipation and other gut diseases such as diverticulitis.  For more information on the health benefits of dietary fibre please visit the British Nutrition Foundation website and the government Eat Well website

If you feel that you are regularly not getting enough fibre from your diet it is important to see if you can find ways to increase the amount of vegetables, fruits, beans/pulses and wholegrains into daily meals.  There are also many fibre supplements available but these lack the other nutritional benefits provided from plant foods (e.g. vitamins and minerals) that plant foods contain.  One supplement that may be worth considering is FOS, fructo-oligosaccharides, since this provides a form of fibre but is also a prebiotic and hence has other health benefits.  A prebiotic is a food that stimulates the growth of the beneficial bacteria already present in the colon.  In October I wrote a post about evidence linking prebiotics to reduced appetite and increased satiety.  Just 5g daily could be beneficial for a number of reasons as well as boosting fibre intakes.

(1)Buttriss JL & Stokes CS.  2009.  Dietary fibre and health: an overview.  Nutrition Bulletin.  33:186-200
(2)Huaidong Du et al.  2010.  Dietary fiber and subsequent changes in body weight and waist circumference in European men and women.  American Journal of Clinical Nutrition.  91: 329-336
(3) Henderson L et al.  2003.  The National Diet and Nutrition Survey: Adults aged 19-64 years.  HMSO London
Written by Ani Kowal