Advancements in digital health technologies are reshaping the way nutrition professionals assess dietary behaviors, metabolic responses, and overall health. This chapter examines how mobile applications, wearable devices, physiological sensors, continuous glucose monitors (CGMs), immersive virtual reality tools such as IVAN, and advanced biomarker testing enhance the precision and personalization of nutritional assessment. By integrating real-time data, behavioral insights, and biological indicators, these technologies support individualized dietary strategies that move beyond generalized recommendations. The chapter highlights how technology-driven assessment improves monitoring, supports behavior change, and enables more responsive, evidence-based nutrition interventions.