Dietary functional mechanisms examine how nutrients and bioactive compounds interact with the body to support health and prevent disease. Carbohydrates, proteins, and fats have distinct metabolic pathways, each serving specific roles from energy provision to muscle maintenance. Bioactive compounds, such as flavonoids found in fruits and vegetables, support immune function and protect against oxidative damage, contributing to chronic disease prevention. Fiber impacts gut health by feeding beneficial bacteria, influencing digestion, and reducing inflammation. Additionally, vitamins and minerals act as co-factors in various biochemical processes. Understanding these mechanisms helps inform dietary recommendations that optimize nutrient intake for health outcomes, enabling individuals to make food choices that enhance metabolic health, reduce disease risk, and promote overall wellness.