This article describes age-specific characteristics that inform how children and adolescents interact with their food systems and how that relationship influences their diets, using the socio-ecological framework. It highlights the fact that various interpersonal, intrapersonal, and environmental factors influence the diets of indivduals across the life cycle, particularly children and adolescents, and that these factors can pose challenges to the attainment of optimal diets in children and adolescents.