Obesity has been estimated to cost the EU some €70 billion annually through health care costs and lost productivity, and additionally overconsumption of salt, sugar and saturated fats and under-consumption of fruit and vegetables cause almost 70,000 premature deaths annually in the UK alone. Member states have initiated a variety of policy interventions to encourage healthy eating, including prohibitions on advertising certain foods to children, promotion of fruit and vegetable consumption, nutrition labelling, dialogue with food industry to improve food product composition and regulation of school meals and public sector canteens to ensure healthy food offerings. Rarely have these been evaluated in a systematic manner. The EATWELL project will gather benchmark data on healthy eating interventions using a 3 stage procedure: (1) The impact of the intervention on consumer attitudes, consumer behaviour and diets; (2) The impact of the change in diets on obesity and health; (3) The value attached by society to these changes, measured in life years gained, cost savings and QALYs. Where evaluations have been inadequate, EATWELL will gather secondary data and analyse them using models mainly from the psychology and economics disciplines. Particular attention will be paid to lessons that can be learned from the private sector that are transferable to the healthy eating campaigns in the public sector. Through consumer surveys and workshops with other stakeholders, EATWELL will assess the acceptability of the range of potential interventions. Armed with scientific quantitative evaluations of policy interventions and their acceptability to stakeholders, EATWELL will recommend most appropriate interventions for Member States and the EU, provide a one-stop guide to methods and measures in interventions evaluation, and outline data collection priorities for the future.