**1. Introduction**

Lifestyle choices can have a tremendous impact on people's health and wellness. Avoiding unhealthy habits is nowadays a priority, and to achieve this goal, ground-breaking mechanisms are required to automatically and autonomously identify and eventually change people's behaviors. An increasing number of smart, ubiquitous sensing technologies are being developed all over the world to coach people on healthier and more responsible behavior, providing them with timely personalized information and support. This Special Issue aims at bringing together the latest experiences, findings, and developments on smart sensing, modeling, and understanding of human behavior for the provision of personalized coaching and support services.
