Bodybuilding athletes often face challenges in maintaining a diet that aligns with their training and performance goals. This project addresses that issue by developing the Diet Advisor app—a Flutter-based mobile application that offers personalized diet and exercise recommendations based on user profiles and daily activities. The system integrates three core components: user profiling, AI-driven recommendations, and data visualization. Key challenges included accurate data plotting, exercise tracking, and handling incomplete user profiles. These were addressed through adaptive UI design and fallback mechanisms [10]. Two experiments tested the AI's reliability in calculating BMR and generating diet plans. Results demonstrated strong accuracy and high practical value, with no significant discrepancies in BMR values and consistently high ratings for dietary recommendations. Compared to existing AIbased systems, this app provides superior precision and adaptability for bodybuilding needs [1]. Its user-friendly design and scientific basis make it a promising tool for promoting performance-oriented and sustainable nutritional practices.