1 People with diabetes should consume at least the recommended amount of fiber for the general population: about 25 grams per day for women and 38 grams per day for men. 2  Many Americans only get about half of what is recommended. People with diabetes should consume at least the recommended amount of fiber for the general population: about 25 grams per day for women and 38 grams per day for men. 2  Many Americans only get about half of what is recommended.