The Institute of Medicine of the US National Academies recommends a daily dose of 20-35 grammes of fiber for every adult. Nevertheless an average American consumes just 12-18 grammes.1
The American Dietetic Associate recommends an intake of 20-35 grammes of fiber for a healthy adult, the precise dose depending on the daily total amount of calories. Thus a daily diet of 2000 kcal should include 25 grammes of fiber. In relation to children, ADA recommends a daily dose of fiber worked out according to the following calculation: age + 5 = grammes of fiber. For example: a child of 4 should consume 9 grams of fiber daily. There are no recommendations for elderly people or those very ill. People suffering from constipation, vomiting or stomach pains should contact their doctor.
British Nutrition Foundation recommends that every healthy adult should have 18 grams of fiber in their daily diet.