Supermarkets are important settings for dietary interventions and there is growing evidence that in-store interventions, such as signage and price discounts on healthier foods, can be effective. However, often research interventions are not rolled out in the real world because they are not cost-effective for the retailer. A New Zealand retailer-academic collaboration aimed to co-design commercially sustainable strategies to increase sales of healthier foods relative to less healthy foods in a major supermarket chain. Two co-design workshops were held, led by an experienced facilitator and involving supermarket corporate strategy team members and public health nutrition academics. Potential interventions were mapped against choice architecture evidence frameworks and retailer strategic priorities before one intervention, more prominent shelf placement of healthier products, was selected for evaluation. A 10-week controlled trial was undertaken in six supermarket stores (three intervention and three control stores) April-July 2019. Products in one selected category were ranked by healthiness (nutrient levels and nutrient profile), and their shelf placement was altered in intervention stores so that healthier products were placed at eye level and less healthy products were placed on lower shelves. No changes were made to shelf layout in matched control stores. The primary outcome of interest is change in sales of healthier products relative to total category sales. Sales relative to pre-intervention and post-intervention periods will also be evaluated. Secondary outcomes include overall nutrient profile of category products sold, customer expenditure, customer perceptions, and retailer feedback. The intervention phase will be complete in July 2019 and results will be presented at the ANZOS conference. Funding source: Health Research Council of New Zealand “Dietary Interventions: Evidence & Translation (DIET)” programme grant (18/672)