Most dietary recommendations are based on studies of limited power and do not adequately reflect the current knowledge base, particularly with regard to effects of diet on clinical outcomes, the most important endpoint from the patients' perspective. In this review we discusses the current state of dietary research, and present a summary of the evidence upon which to base dietary recommendations and guidelines for atherosclerotic vascular disease prevention. We also highlight the complexity and limitations of interpreting current diet-based epidemiological studies in isolation.