PAS GRAS aims to prevent and reverse obesity and associated metabolic complications in four age groups: pre-pubertal children (3-9 yr), adolescents (10-18 yr), young adults (19-25 yr), and adults (25-55). PAS GRAS focuses on four main pillars. 1) Develop a personalized risk assessment tool (RAT): an algorithm that will anticipate obesity priming and development in the critical age groups, and identify risk factors for specific complications in subsequent years that will constitute new outcomes for interventional studies. 2) Develop and implement RAT-based personalized interventions by integrating non-pharmacological lifestyle modifications including Mediterranean Diet components alone or with rational pharmacological targeting metabolic and neuroendocrine mechanisms. 3) Inform and engage effectively target groups on obesity causes, risks and intervention by co-production of creative and interactive digital tools (including a simpler version of the RAT) and personalized diet and physical activity programs. 4) Expand and consolidate the PAS GRAS tailor-made campaign across Europe through developing joint programs for health and food/nutrition literacy and physical activity, with healthcare centres, schools, sports clubs, municipalities, and other relevant actors and public authorities. PAS GRAS outcomes will contribute to a long-term 15% decrease in overweight/obesity prevalence in adults and 30% in children/adolescents in the EU until 2050, contributing to a downstream reduction of obesity-associated complications, pharmaceutical and surgical interventions, and to promote Mediterranean Diet as tool for a more nutritious and sustainable future. PAS GRAS is a unique multi- and interdisciplinary research team from 8 countries, including 12 top-level Universities and Research Institutions. Nonacademic partners include a civil organization, one company, one patient organization and one Pan-European research Society.