Fiber absorbs liquids in the digestive system, thereby bulking up fecal matter. It is recommended that women under 50 consume 25 grams of fiber per day. A woman over 50 years of age should consume 21 grams per day. Men younger under 50 are recommended to get 38 grams per day. Men over 50 should get 30 grams per day in his diet. The average American, however, only has about 15 grams of fiber per day in his or her diet. And what is fiber therapy? Fiber therapy is simply increasing your fiber intake gradually until you reach the recommended daily intake for your age.