In the frame of the PEGASO European project, we aim at promoting healthier lifestyles among teenagers focusing on the alimentary education and physical activity. This paper presents a novel concept of mobile food record developed following a multidisciplinary approach to innovate both the monitoring and the user experience. This mobile food record does not count calories but is focused on tracking dietary patterns and support the adoption of target behaviours. Moreover, the introduction of game mechanics developed through participatory design techniques aims at sustaining engagement in the long term.