Explore a conference talk that delves into the integration of behavioral theories with persona creation, focusing on a case study using Self-Determination Theory (SDT) to develop overweight personas. Learn how SDT can enhance the persona development process, providing insights into users' motivations and psychological needs for sustainable behavior change. Discover the methodology used to prepare and analyze interviews, create complex and realistic personas, and make users' basic psychological needs explicit. Gain valuable knowledge on the challenges and strengths of incorporating behavioral theories in persona creation, and understand how this approach can contribute to designing more effective digital health interventions for sustainable weight loss.