Guidelines on diet and nutrition serve two important purposes: to guide policy makers and to educate consumers, be they healthy or ill, about healthful ways to eat. Other lifestyle behaviors such as weight, physical activity and smoking status are sometimes also included. The soundness of the resulting guidelines depends on the strength of the evidence attesting to the presence of diet-health relationships. Precedent and the larger environment also have powerful influences. The degree to which guidelines are used will depend on how well they are crafted with respect to communication and how the recommendations are publicized. Holistic approaches rather than single silver bullet approaches that are targeted to reduction in risks of dietary deficiencies, food-borne illnesses and multiple chronic degenerative diseases are probably the most useful for the nutrition education of the public. The Dietary Guidelines for Americans are one example. Such dietary and nutritional recommendations based on sound science, reviewed periodically and communicated effectively have a positive and helpful role in cancer prevention and risk reduction.