School meals present several cost benefits overtime at the short, medium, and long term for individuals and society. This cross-sectional study aims to analyse the nutritional composition and evaluate the adequacy of school lunches. One hundred and fifty-eight samples were collected and analysed from 10 primary schools in Sintra’s municipality, served during one week. On average, energy (27.7% daily energetic requirements) and carbohydrate (48.1%) contents did not reach the reference values, and the content of protein (19.5%) exceeded the reference value (p < 0.05). The mean total fat (28.8%) and saturated fatty acids (5.4%) content complied with the recommendations. The mean salt (1.7 g) and dietary fibre (8.3 g) content exceeded the reference value but did not differ significantly from the recommendations. Addressing school canteens is crucial, not only in a nutritional approach, but also as an opportunity to achieve healthier, sustainable, and accessible food systems, aligned with the Sustainable Development Goals 2030. We highlighted the importance of evaluating evidence-based practices and disseminated practice-based evidence regarding the adequacy of school lunches.

Policy interventions in the school food environment can improve dietary behaviors. However, the literature describing its development and implementation is scarce. This manuscript aims to describe the process of co-creation, implementation, monitoring, and evaluation of a Healthy Snacks Policy, in the scope of Sintra Grows Healthy intervention. Through a community-based participatory research methodology, the co-creation of the Healthy Snacks Policy comprises six stages: snacks evaluation, feedback sessions, class assemblies, school community assemblies, school cluster policy approval, and process evaluation. Within one school year, a Healthy Snacks Policy was co-created, approved, incorporated in the school regulations, implemented, continuously monitored, and evaluated. Regarding snacks evaluation, 1900 snacks were evaluated at the beginning of the school year and 1079 at the end of the school year. There were three feedback sessions, twenty-two class assemblies, and three school community assemblies. Most teachers perceived that children began to consume healthier snacks (72%); 66% of the children were considered to have started eating healthier; and most families said “yes or sometimes” when asked whether their children started requesting healthier snacks (70%), trying new foods (63%), and noticing improvements in their eating habits (74%). The co-creation of a Healthy Snacks Policy establishes an approach to effectively implement existing guidelines for school food supplies, complying with national priority implementation recommendations.