Adolescent and emerging adult obesity presents growing public health challenges. Yet, limited research explores the lived experiences of young individuals engaged in real-world weight loss interventions. This study aimed to explore the lived experiences of obese students participating in a structured campus-based weight reduction program, with a focus on their motivational triggers, perceived challenges, applied strategies, and sources of sustained motivation. A qualitative descriptive design was adopted. Three obese students (aged 18–21) from a nursing junior college in northern Taiwan were individually interviewed. Data were analysed using Colaizzi’s method to identify key themes. Four major themes emerged: (1) Motivation to initiate weight loss (e.g., weight stigma, physical discomfort); (2) Challenges during the process (e.g., emotional eating, exercise barriers, health risks from extreme methods); (3) Effective strategies (e.g., goal-setting, dietary tracking, professional guidance); (4) Sustained motivation (e.g., social support, belief in personal change, confidence from visible improvements). Participants demonstrated complex emotional and behavioural journeys shaped by personal, social, and programmatic factors. The findings underscore the importance of integrating psychological support, family involvement, and structured professional guidance to enhance long-term weight management for obese emerging adults.