The present proposal focuses on overweight and obesity as one of the main determinants of loss of healthy life years and of health disparities in Europe. In particular, it focuses on expanding understanding of the key lifestyle factors nutrition and physical activity, which are the major proximal determinants of overweight and obesity. It aims at identifying (I) socio-economic and environmental determinants of these behaviours and (II) effective intervention settings and apporaches to address these determinants aiming at obesity prevention and reductions in inequalities in obesity-related health risks.