The global surge in non-communicable diseases (NCDs) necessitates a transition from episodic clinical care to continuous, data-driven personal health management. This paper details the development of the Smart Health and Fitness Tracker (SHFT), a scalable ecosystem built on the MERN stack. Unlike localized tracking applications, SHFT employs a centralized NoSQL architecture to provide longitudinal health data analysis. The system integrates real-time telemetry tracking—including caloric balance, hydration, and sleep hygiene—with automated BMI and BMR computation. By utilizing a React-based interactive dashboard and Node.js middleware, the platform achieves high data integrity and low-latency feedback. Experimental results demonstrate that the system enhances user engagement and supports informed decision-making for long-term wellness.