AbstractBackground: Front-of-package (FOP) nutrition labelling has become a core component of policy recommendations to address the growing burden of diet-related non-communicable disease globally. The CODEX Committee on Food Labelling is in the process of establishing standardized criteria for the definition of “high-in” for use with FOP labels highlighting excessive amounts of fats, sugars and sodium in foods. Recently, as part of Health Canada's Healthy Eating Strategy, regulations requiring the mandatory display of high-in FOP symbols have been published. The aim of this study was to investigate the extent to which these symbols would appear on foods and beverages in the Canadian prepackaged food supply, both overall and by food category.Methods: Foods and beverages in the University of Toronto's Food Label Information Program database 2013 (n = 15,277) were assessed for the prevalence of products that would have to display a symbol based on criteria published in the draft Canadian regulations. The criteria include thresholds based on the % Daily Value (DV) for each nutrient, above which, products would be required to display a FOP symbol for that nutrient. Exemptions are provided for fruits and vegetables without added sodium, sugars, or saturated fats, non-flavoured whole or partly skimmed milk, eggs, sweetening agents (i.e. sugar, honey, syrups and molasses) and table salt.Results: 61.7% (n = 10,251) of products would be required to display at least one symbol. Of these, 52.3% (n = 5,358) would have a sodium symbol, 41.9% (n = 4,295) a saturated fats symbol and 41.0% (n = 4,207) a sugars symbol. Overall, 37% of products would display a symbol for more than one nutrient. The highest concentration of symbols were found on processed meats (93.8%), soups (93.0%), desserts (87.2%), sugars and sweets (82.3%), dairy (76.9%) and bakery products (71.0%).Discussion: This is the first study to evaluate the impact of proposed regulations for the mandatory display of FOP symbols on Canadian prepackaged foods. Findings identify a high concentration of symbols in categories contributing meaningfully to dietary sodium, sugars, and saturated fats intakes, but also in categories for which consumption is discouraged in national dietary guidelines (e.g. processed meats, desserts). The findings presented here will inform ongoing discussions on how best to optimize criteria underpinning the display of FOP “high-in” labels.