How much fibre do I need and why?

The official recommendation for adults aged 19 to 50 is 38 grams of fibre per day for men and 25 grams for women. That is more than most people consume on a daily basis. Note: these figures apply to healthy individuals; if you have a chronic condition, the recommendation may differ.

Fibre comes in two types, each with a different effect. Soluble fibre, found in oats, fruit, vegetables and barley, can lower blood cholesterol. Insoluble fibre, found in wholegrain products, bran, nuts and seeds, speeds up intestinal transit and makes your bowel movements more regular. Both types are therefore useful, but for different purposes.

There is also a benefit for your heart: eating more fibre is associated with a lower risk of cardiovascular disease and atherosclerosis. This comes from observational research, which means we can see a clear association but cannot establish a watertight cause-and-effect relationship.

Exercising or pregnant? A small study in pregnant women with type 1 diabetes found that a higher fibre intake was associated with 16 to 18 percent less insulin requirement per day, although this is an association, not a proven cause. For athletes, no official fibre guidelines exist yet, but in sports nutrition circles a gradual build-up to around 30 grams per day is recommended to support gut health.

One point of attention with a very high-fibre diet: there are indications that a very high intake may slightly increase the need for copper. The evidence for this is limited and fairly old. For most people who reach the standard amount this is not an issue, but anyone who wants to eat drastically more fibre than recommended may find it wise to continue eating a varied diet in order to avoid deficiencies.