This data set contains all gather information of the MyMovez project, which investigated adolescents’ health behaviors (ie., nutrition, media use, and physical activity) and their social networks for three years. The first year (2016; data collection waves 1, 2, 3) and the second year (2017; wave 4) marked the first phase of the project in which the health behaviors of adolescents were monitored without intervening. The third year (waves 5, 6, 7) marked the second phase of the project in which four different types of interventions were tested to promote either water consumption or physical activity. A fifth group did not receive an intervention and is used as a control condition. During the measurement periods, participants received the MyMovez Wearable Lab: a smartphone with a tailor-made research application and a wrist-worn accelerometer. The accelerometer (Fitbit Flex) measured the physical activity per minute and per day, and was water-resistant. The smartphone was equipped with a custom made research application by which daily questionnaires were administered. Beginning in wave 5, the app contained a social platform in which the participants could communicate with each other. The smartphone also connected to the accompanying accelerometer and other research smartphones via Bluetooth. Among others, the most important measures in the project are: - Questionnaire data: e.g. Food Frequency Questionnaires, Self-reported media exposure, measures related to the theory of planned behavior - Physical activity measured by accelerometer. - Sociometric nominations: Peers nominated classmates on certain questions - Proximity networks inferred from the Bluetooth connections on the research phones (beacon data) - Online communication data derived from the social platform (Social Buzz) - Photo data (not shared in this repository) - BMI measured by the researchers For more information please see the accompanying overview, or the protocol paper of the project: ...