Maintaining weight loss is challenging for patients who suffer from obesity as behavior changes need to be kept long-term. Prior research has shown that introducing habitual behavior (ie, habits) can lead to automaticity in performing a specific behavior so that it becomes second nature. This researchand-progress paper develops a research model to investigate the efficacy of virtual coaches to guide patients in forming habits. In particular, we investigate how virtual coaches can help patients form an implementation intention for a particular habit and positively reinforce this implementation intention using reminders, praise, and self-monitoring. Implications of this work are described for related diseases and long-term evaluations of virtual coaches.