The Policy Options for Responding to the Growing Challenge of Obesity Research Project (PorGrow) study was conducted at a time when the prevalence levels of overweight and obesity among both adults and children had been rising for over a decade in most countries in Europe. The reasons are assumed to be related to changes in dietary patterns and in patterns of physical activity, and may be linked to economic as well as socio-environmental influences on behaviour. Inequalities in the distribution of obesity across different socio-economic groups are also apparent. The demographic and secular trends have led to increasing concern among policymakers over the costs of obesity-related disease to the health services and to the economy generally. In response, a series of policy initiatives have been considered among the countries participating in the PorGrow study.