Eat high-fiber cereals. The benefits of fiber are far reaching. From digestion to diabetes to cancer, fiber is responsible for improving these conditions. A person should consume 25 to 35 grams of fiber a day. While many people get their daily intake of fiber from fruits and vegetables, high-fiber cereals such as All Bran (1/3 cup = 8.5 grams), Fiber One (1/2 cup = 14 grams) and 100% Bran (1/2 cup = 8.4 grams) are all optimum sources for fiber.