Large, prospective, epidemiologic studies show a protective effect of dietary fiber against coronary heart disease (CHD) and form the basis for new recommendations from the National Academy of Science for fiber intake (38 and 25 g/d for young men and women, respectively, based on an intake of 14 g of fiber per 1000 kcal). Mechanisms by which fibers may protect against CHD include lowering blood cholesterol (soluble fibers), attenuating blood triglyceride levels (mostly soluble fibers), decreasing hypertension (all fibers), and normalizing postprandial blood glucose levels (all fibers). An important consideration in making diet recommendations to protect against CHD is that the total amount of fiber from fiber-containing foods is important, and individuals should not just be counseled to focus on soluble fiber.