Adolescence is a critical period for physical and psychological growth and development when individuals undergo a burst growth in physical size, hormonal re-adjustment, and brain development. In recent years, research studies have changed from descriptive growth charts toward focusing on the roles of multiple factors that affect adolescent health, including epigenetic regulators, genetic traits, social stressors, and gut microbiota. Compared to traditional factors like nutrition and hormones, environmental factors, personalized genomics, social media exposure, and gut-microbiome, etc. are increasing recognized as novel critical regulators of adolescent health. Currently, the goal of academic research in adolescence is to understand the interactions and underlying mechanisms of these factors and to develop targeted interventions for addressing adolescent health issues. Therefore, this chapter mainly discusses the new trends, key challenges, and translational research potential in these rapidly advancing field of adolescent growth and development.