However , research has shown that the average American only consumes 14 to 15 grams per day .
The American Dietetic Association recommends that the average adult consume 25 to 38 grams of dietary fibre per day .
Research has shown that the average American only consumes 14 to 15 grams per day .
The American Dietetic Association recommends that the average adult consume 25 to 38 grams of dietary fibre per day .