Fiber intake has fallen considerably over the centuries. In Paleolithic diets, it was estimated to be 77 to 120 grams per day.8 Traditional diets are estimated to have 50 grams per day of dietary fiber.9 By contrast, modern American diets contain as little as 15 grams per day.10 Indeed, even the American Heart Association’s Dietary Guidelines for Healthy North American Adults only recommends 25 to 30 grams per day.11
