Reducing sodium consumption is an effective means of lowering blood pressure and thus cardiovascular risk. Reducing sodium consumption in the clinical and public health contexts has proven difficult. Three approaches will inform attempts to reduce sodium intake in NZ. First, analysis of the 2008/09 National Nutrition Survey data will enable an estimation of intake and source of dietary sodium, international comparisons, and development of an approach to monitoring. Second, in-depth interviews will explore consumers' understanding of 'salt' and 'sodium', their knowledge of its health effects, and their use of food labels. A quantitative study will estimate the interaction between consumers' knowledge of sodium, their response to food label formats, and their choice behaviour. The results will inform the design of a randomised controlled trial that tests an intervention to lower sodium intake.