Summary Awareness of the increased prevalence of heart disease, obesity and type 2 diabetes has resulted in research being focused on simple and robust approaches to their prevention. One rationale for dealing with these potentially major public health problems is via a better understanding of the contribution of diet to progression towards these diseased states. As a response to these concerns, major research efforts in this area have been funded under the auspices of the European Union. In particular, studies are aimed at providing the scientific basis for improving health through diet, with a focus on understanding how polyunsaturated fish oils can be a positive (i.e. protective) component of diet against metabolic syndrome (the descriptor for progression towards diseases such as obesity and type 2 diabetes). This review will consider the health implications of the rise in metabolic syndrome, as well as new approaches to the provision of beneficial polyunsaturated oils.