The UK Government’s Responsibility Deals (Food Network) seeks to promote healthier dietary choices by consumers through food industry-led product reformulation initiatives enhancing the availability of healthier foods. Such public-private partnerships based on voluntary action from the food industry are part of the “nudge” agenda and are seen as preferred alternatives to more intrusive regulatory and fiscal interventions in food product markets. This paper develops a framework to assess the potential effectiveness of Responsibility Deals in influencing the population level intakes of energy and nutrients. Our analysis finds that Responsibility Deals, even if wholeheartedly adopted by the food industry, may not necessarily lead to significant reductions in population level energy and nutrient intakes. This is because the effect of product reformulation initiatives is mediated by consumer response to these initiatives both within and across major food product groups. Our results suggest that the major role for Responsibility Deals lies not in “nudging” consumers towards healthier dietary choices, but rather in reversing or halting the trends in food product nutrient composition changes over the last two decades that have rendered adherence to recommended dietary guidelines more difficult for consumers. Discussion paper presented at the 89th Annual Conference of the Agricultural Economics Society, University of Warwick, United Kingdom. April 13-15, 2015 Draft discussion paper: Corresponding author: c.s.srinivasan@reading.ac.uk , School of Agriculture, Policy and Development,