Dynamics of sedentary behaviours and systems-based approach: future challenges and opportunities in the life course epidemiology of sedentary behaviours

This chapter challenges our current thinking about sedentary behaviours and offers new paradigms to move forward to understand the complex nature of sedentary behaviours and their determinants. Sedentary behaviours are ubiquitous and changing in nature over time: with advances in media and IT, TV time is decreasing, but overall screen time is growing. Understanding the non-linear temporal dynamics of sedentary behaviours and how people accumulate, or break, sitting time appears a crucial step to design innovative strategies. Since multiple factors at different levels (proximal, distal) are interacting to drive sedentary time, new perspectives combining a life course perspective and complexity science are needed. Systems-based approach and adaptive dynamical systems modelling will help model the interaction between factors and feedback loops. A systems-based framework for the study of sedentary behaviours called SOS (Systems of Sedentary behaviours) has been established by a transdisciplinary research group within the framework of the European DEDIPAC Knowledge Hub. Novel methods of enquiry are required to progress the field, including methodologies for analysis such as probabilistic modelling techniques (Bayesian networks), simulation studies investigating different scenarios of possible societal changes and their effect on sedentary behaviours, and innovations in measuring accurately other dimensions such as context and type of sedentary behaviours. Finally, future opportunities for innovative data collection and analysis (big data) and innovative interventions (natural experiments, solutionist, and participatory approach) are highlighted for their potential to benefit sedentary behaviours research and work more efficiently towards public health solutions to tackle this new threat of modern life.