With the advancement of digital technology, excessive screen media use has become a serious concern among researchers and practitioners. Screen time during COVID-19 has further increased, as a result of public health measures enforced by governments to curb the pandemic. However, a comprehensive overview on screen use in young children (0-5yrs) and long-term impact on children’s obesity and mental health symptoms is lacking. The SCREENHEALTH Project will be the first Portuguese 3-yr prospective study to document the impact of screen use trajectories on obesity and mental health among preschool children. It aims to:

1) identify the trajectories related to screen use in children aged 3-5yrs;

2) identify the socio-ecological factors that predict trajectory membership,

3) analyze the association between screen use trajectories and health-related behaviors, and

4) assess causal pathways (& direction) linking children’s screen use trajectories, obesity and mental health.

The Project will adopt a socio-biological approach to follow a large sample of 3-5-yr-old children from Coimbra, Portugal. An interdisciplinary and integrative methodology (i.e., questionnaire and accelerometer) will provide cross-validation. Our innovative approach will address significant research gaps, including

1. i) the identification of opportunities to intervene early and influence behavioral trajectories and

ii) the provision of youth appropriate thresholds for screen use, in specific screen devices, beyond the basic 1h cut-off of ST currently used. SCREENHEALTH will set the ground for longitudinal explorations in the national and international context.

SCREENHEALTH’s objectives yield unique and important insights about which children are most at-risk of falling into screen use trajectories that lead to poor weight status and mental health, increasing our ability to prevent these unhealthy behaviors prior to their onset. Detection will also be improved by providing more refined categories of ST (total and device-specific).

1. Literature review & study preparation
2. Data collection (Wave 1)
3. Data processing, analysis & dissemination (Wave 1)
4. Data collection (Wave 2)
5. Data processing, analysis & dissemination (Wave 1+2)
6. Data collection (Wave 3)
7. Data processing, analysis & dissemination (Wave 1+2+3)
8. Project management & coordination