This World Health Organization (WHO) guideline provides a comprehensive overview of the intake of saturated and trans-fatty acids for adults and children, aiming to reduce the risk of cardiovascular diseases (CVDs). It highlights the correlation between high levels of these fatty acids and increased risk of CVDs, which are a leading cause of death worldwide. The document outlines evidence-based recommendations for reducing intake by replacing saturated fatty acids with unsaturated fatty acids or whole grains. It also discusses the impact of these dietary changes on blood lipids, cholesterol levels, and overall heart health. The guideline is targeted at health professionals, policymakers, and public health officials to guide dietary recommendations and interventions.