Background and Objective: Current global food systems are unhealthy, unjust and environmentally unsustainable. Transitioning to healthy and sustainable food systems is challenging; needing “double and triple-duty actions”, which are interventions and policies that have the ability to simultaneously reduce the risk or burden of undernutrition and/or overweight, obesity and/or climate change. Therefore, we propose the use of different policy indicators to inform policymakers in the design and implementation of policies towards healthy diets from sustainable food systems. Methods: Through a compilation of international recommendations, a scoping review, four regional workshops with food policy experts, eight country-based policy mappings and policy stakeholder interviews, the International Network for Food and Obesity/NCDs Research, Monitoring and Action Support (INFORMAS 2.0) Aims to create a new Food Systems Policy Index to monitor governments’ actions on sustainable food systems. The tool will take into account the impact of policy indicators on obesity/non-communicable diseases, undernutrition and environmental sustainability. Two secondary outcomes (nutrition inequalities and women’s empowerment) will also be considered. Results: A total of 291 international policy recommendations have been compiled, classified and merged into two policy domains (food supply chains and food environments) and ten subdomains (including, among others, agriculture, food waste and labelling) that impact food security, obesity and/or climate change. Their effect has been assessed both in a scoping review and through a survey, four workshops and a ranking consulting international experts, to decide the final list of 44 policy indicators with double and triple-duty potential. A mapping of the policies and interviews with national and local policy stakeholders from eight countries is be conducted to pilot test the policy index. Conclusions: Given the heterogeneity and complexity of food systems, the index will represent a useful tool for governments to tackle malnutrition in all its forms, nutrition-related inequalities, climate change and biodiversity loss.