Food processing-based classification systems have been increasingly acknowledged in reports and commentary from the World Health Organisation, Food and Agriculture Organization of the United Nations, and the Pan American Health Organization. The aim of this issue was to examine the role and utility of food processing-based classification systems in food and nutrition research and public policy. This issue shows that food processing-based classification systems: - offer possibilities for use in public policy as a way to define unhealthful dietary patterns. - may underpin other regulatory strategies for the prevention and control of obesity and diet-related non-communicable diseases by identifying unhealthful foods. - could also be applied in local planning regulations, where these seek to influence the availability or accessibility of foods in local environments Authors conclude that food processing-based classification systems have a great potential for wider application in food policy.