This thesis aims to understand how public health evidence can be used better to inform the development of food and agriculture policy. It sets out to achieve this by developing and applying two methods that have been advocated for use in evidence-based policy making: health impact assessment (IDA) of agriculture and food policy and calculation of the burden of disease attributable to nutritional risk factors. Neither of the methods had previously been used in this policy context. They were selected as they illustrate two extreme models of evidence-based public health. The first consists of research based, investigator-led analysis producing generalisable, quantitative estimates. The second involves a more contextual, participatory, inter-sectoral approach to collecting. analysing and applying a broader range of data. The methods have been developed and applied using the fruit and vegetable sector as a case study, with specific reference to policies in the Republic of Slovenia, a country that was, during the course of this work, acceding to the European Union and presented a unique political opportunity. This thesis explores how these different evidence-based public health approaches are likely to inform policy, in the light of what we already know about influences on policy making. This thesis finds the total worldwide mortality currently attributable to inadequate consumption of fruit and vegetables is. estimated to be up to 2.635 million deaths per year. Increasing individual fruit and vegetable consumption to up to 600 g per day (the baseline of choice) could reduce the total worldwide burden of disease by 1.8%, and the burden of disease in Slovenia by 2%. The greatest impact would be on reduction of ischaemic heart disease and ischaemic stroke. However, such descriptive epidemiology is an insufficient basis for policy formulation as the results say nothing about how interventions are likely to reduce a problem The results of the health impact assessment show that evidence demonstrating priorities for public health action will be different from the type of evidence required for planning, policy implementation or evaluation.