A small-scale trial intervention aimed to reduce the carbon footprint of school meals while keeping the meals as similar as possible to those usually served and ensuring their nutritional adequacy and affordability. The lunch menu was developed through a method called “linear optimisation” and was delivered over four weeks in seven Swedish schools.
According to the IPCC, about 25% to 30% of total greenhouse gas emissions are from the food system, and unhealthy diets have a considerable impact on health. The burden of non-communicable diseases (such as strokes and heart diseases) is increasing, and unhealthy diets account for up to 11 million avoidable premature deaths per year. In Sweden, nearly 200 million meals are served in 5,000 primary schools for school children aged 6 to 16 years, annually, and about 70% of pupils eat these school meals each day. School meals have the potential to influence children's food choices and diets so they adopt more sustainable and healthy patterns throughout their life, and these meals can be made to have a lower burden on greenhouse gas emissions.
This intervention, which aimed to reduce the carbon footprint of school meals while keeping the meals as similar as possible to those usually served and ensuring their nutritional adequacy and affordability, was implemented in a pilot project over four weeks in seven Swedish schools. The lunch menu was developed through a method called “linear optimisation”, which resulted in no foods being removed entirely and no new foods added to the menu. Instead, the lunch menu was optimised to have a lower climate impact while retaining the same nutritional value and cost. The new menu was developed with minimum deviation from the original. Some adjustments had to be made at the meal planning stage, as school chefs deemed these necessary to increase the acceptability of the meals.
A 28% to 40% reduction in CO2 equivalent (CO2eq) was measured, from 829g CO2eq or 693g CO2eq (depending on the baseline level in the school) to 496g CO2eq per meal (savings of 333g to 195g CO2eq per meal). Food waste and consumption was also measured during the implementation of the programme and was found to be similar compared to pre-intervention levels. Therefore, the programme did not increase food waste or reduce consumption.
The programme was only implemented for four weeks, hence no long-term health outcomes were expected or measured. Since the new menu was optimised to retain the same nutritional value as the original menu, it is assumed that this had a net neutral effect on health.
In Sweden, nearly 200 million meals are served in Sweden's 5,000 primary schools for school children aged 6 to 16 years, annually, and about 70% of pupils eat these school meals each day. If the reduction of 331g CO2eq per meal was applied to all school meals served in Sweden, this would result in a total reduction of 66 kilotons of CO2eq annually, achieved from changing only one school meal.
For this to be possible, barriers to the acceptability of these changes must be addressed. A qualitative study was conducted among kitchen staff and students to understand factors that could facilitate or challenge the acceptability of introducing sustainable school meals at scale. The main barrier among kitchen staff was that dishes in the new menu were more time-consuming to prepare and more difficult to make flavoursome and appealing. Pupils also expressed a preference for plant-based dishes that resembled animal-based foods. A challenge identified among both staff and students is that some lacked awareness of what "sustainable" diets meant. Some interpreted sustainability to mean eating foods that are healthy for the whole body, organic, or those that are long-lasting. The study also highlighted that there is a certain level of peer pressure or imitation among students, whereby if one student expresses a negative attitude toward trying the new plant-based dishes, more students assume this attitude.
There was a perception that the change to the new school meal menus was too large and took place too quickly, and thus acceptability would be more likely if the menu was changed slowly allowing time for plant-based meals to become the new norm gradually, rather than giving the impression that the change was made deliberately, with the aim of forcing a significant change in eating habits (Eustachio Colombo et al., 2021). The taste, smell, and even appearance of the food, and perhaps also its similarity to animal-based foods, will need to be improved in order to increase its acceptability among pupils. Enhancing the understanding of what sustainability means in terms of its beneficial effects for the environment as well as its advantages for health, and changing attitudes among both staff and pupils, are also important factors to help improve acceptability. It may also be beneficial for these efforts to be incorporated into wider changes at the school level, utilising strong organisational support from school leadership and other stakeholders, as well as incorporating classroom activities and training of kitchen staff on sustainability to increase understanding of the relationship between food systems, health and the environment (Eustachio Colombo et al., 2021).