Previously called 'roughage', dietary fibre is found in pulses (half a tin of baked beans provides a third of your fibre intake), cereals, fruits, nuts and vegetables - but there is none in meat or animal products such as eggs.
There are two types of fibre - insoluble and soluble - and both are needed to keep us healthy. 'Insoluble fibre makes food move through the digestive tract more quickly, preventing constipation and reducing the time toxins are in contact with the gut, which may reduce bowel cancer risk,' says Sioned Quirke.
Soluble fibre dissolves inside the digestive tract where it forms a thick gel that helps slow the movement of sugars into your blood and reduces the absorption of cholesterol.