Peru's front-of-package warning label policy and changes in the healthfulness of the food supply: A pre-post observational study

BackgroundIn June 2019, Peru implemented the first phase of a front-of-package warning label (FOPWL) policy, requiring packaged foods and beverages exceeding established thresholds for total sugars, sodium, saturated fats, or containing trans fats to display warning labels. While primarily intended to inform consumers, such policies may also incentivize product reformulation. This study aimed to assess changes in the nutrient content and proportion of regulated products (i.e., "high in" products) in the Peruvian food supply following the implementation of the first phase of the policy. Methods and FindingsA dataset of nutritional information from 2019 to 2021 was developed using product-level data collected at two time periods: preimplementation (T0: March-June 2019; n = 2,481) and postimplementation (T1: March 2020-February 2021; n = 3,018). The proportion of products exceeding regulatory thresholds (per 100 g or 100 mL) for total sugars, saturated fats, sodium, or containing trans fats, as well as quartiles of these nutrients, were compared pre-and postimplementation of the law in cross-sectional samples of products. A longitudinal subsample (i.e., products collected in both the pre-and postimplementation periods, n = 1,694) was also analyzed. Changes in the proportion of "high in" products were assessed using logistic regression models; shifts in nutrient distributions were evaluated using quantile regression models. In cross-sectional analyses over T1-T0 period, the share of "high in" products declined by 6 percentage points, from 62% to 56% among foods and by 11 percentage points, from 32% to 21% among beverages. Relative reductions were observed in products "high in" sugars (10% for foods; 36% for beverages), sodium (19% for foods), and trans fats (41% for foods). The reductions varied across food and beverage categories and were greatest in groups where the regulatory thresholds were set below the 75th percentile of the baseline nutrient distributions. Longitudinal analyses showed results largely consistent with the cross-sectional findings. ConclusionsThe first phase of Perus FOPWL policy was associated with substantial reductions in the proportion of products "high in" nutrients of concern, suggesting that the policy led to reformulation across diverse food and beverage categories. These findings highlight the potential of mandatory FOPWL policies to improve the nutritional quality of the food supply and support population-wide strategies for preventing diet-related diseases as modest percentage-point reductions in "high in" products can yield meaningful health improvements when applied across millions of consumers.