Evaluation of the Ability of Nutri-Score to Discriminate the Nutritional Quality of Prepacked Foods Using a Sale-Weighting Approach

The implementation of mandatory front-of-pack nutrition labelling is currently being discussed in the European Union (EU). The Nutri-Score (NS) was developed in France to empower consumers to make informed and healthier food choices. Based on strong evidence of its efficacy in supporting healthy choices, it has already been implemented for voluntary use in some EU member states, making it relevant to developing a harmonised EU scheme. This study aimed to evaluate the NS’s discriminating ability on products available in the food supply and compare it with Slovenian national nutritional recommendations based on an adapted WHO Europe (WHOE) profile. The innovative approach of the study is that we used sale-weighting to address the public health importance of available foods, with consideration of market share. We profiled 15,822 products available in the Slovenian food supply in 2017. The NS had a high ability to discriminate food products based on nutritional composition. Products that are generally encouraged in dietary recommendations (fruits, vegetables, cereals) had, in most cases, better NS grades than less favourable products (confectionery, snack foods, added fats), which is also in line with the national nutrition policy programme. The discriminating ability of the model was also shown within food (sub)categories (e.g., plain and flavoured yoghurt). Sale-weighting showed that offerings do not always reflect sales. Major differences between offerings and sales were observed for beverages, dairy, fruits/vegetables, and edible oils/emulsions. Additionally, sale-weighted distribution tended towards less favourable nutritional composition, particularly in categories with overall smaller offerings of products with favourable composition. The NS showed moderate agreement with the WHOE profile (κ = 0.57); differences were particularly observed in flavoured yoghurts, juices, cooking oils, and cheeses. Modelling the operation of the NS with representative real-life food samples provided insight valuable for developing and implementing harmonised mandatory front-of-pack nutrition labelling in Europe.