Encouraging people to manage their health is essential in preventing chronic diseases like type 2 diabetes and heart disease. With mobile technologies such as health apps and fitness trackers, monitoring health has become more accessible and affordable compared to doctoral visits and traditional health check-ups. These technologies are, however, mainly used for disease management rather than prevention and there is no common understanding of how they can best be used for preventive purposes. To this end, we introduce the Bitemporal Lens Model a comprehensive method to use mobile technologies for disease prevention. We explain the structure and usefulness of the Bitemporal Lens Model, discuss its advantages and limitations, and present potential use cases.