Abstract: Behavioral intervention improves the efficacy of treatments designed to encourage healthy behaviors such as smoking cessation, adherence to food regimen after surgeries, and avoiding overeating. Aspects of the present disclosure relate to a health monitoring system that leverages wearable sensors, mobile devices (e.g. smartphones), and computer-based servers to monitor the health of a user and provide intervention at opportune moments to encourage healthy behavior. This system provides a scalable and cost-efficient way for health care providers to monitor the behavior of many users and encourage healthy behavior as appropriate.