Your cholesterol levels will go down over time, decreasing your risk of suffering from heart disease. You need 14 grams of total fiber for every 1,000 calories, explains the Colorado State University Extension website. Having an 1,800-calorie-per-day diet means that you need 16 grams of total fiber. A medium, 2 1/2-inch orange has approximately 3 grams of fiber, more than half of which is soluble fiber.