In developed nations, diet is related directly or indirectly to the most prevalent chronic diseases. Research has helped clarify diet-disease relationships and enabled the promulgation of dietary recommendations for chronic disease prevention. We reviewed epidemiologic study results, clinical trial data, and general dietary recommendations from various agencies to develop a set of overall dietary guidelines for the prevention of the most common chronic diseases in the United States, including coronary heart disease, hypertension, cancer, and osteoporosis. Intake of monounsaturated fats, fiber, calcium, vegetables and fruits, and whole grains should be promoted. Consumption of saturated and trans fats, sodium, and refined grains should be minimized. Moderation in alcohol and caloric intake should be encouraged. Although research into associations between diet and disease is constantly in flux, our guidelines are based on replicated findings and provide a starting point for assisting patients in improving their diets.