Optimizing school meals today : a pathway to sustainable dietary habits tomorrow

Abstract

Food production and consumption substantially contribute to climate change and disease. School meals can reach children of every socioeconomic background and hold a near-unique potential to foster sustainable dietary habits in the young generation in both the short and long term. This thesis explored a pathway to designing and introducing children to climate friendly, nutritious, affordable and culturally appropriate — i.e. sustainable — school lunches.

Study I explored the importance of school lunches to children’s overall diets in Sweden. Dietary intakes of nutrients and food groups were calculated and compared between girls and boys as well as by pupils’ parental education. School lunches accounted for almost half of pupils’ vegetable intakes. The nutrient density was higher, and energy density lower, at lunch compared to foods consumed during the remaining weekday. Boys had higher intakes of red/processed meat, but lower intakes of dietary fiber and vegetables than girls. Differences in dietary intake based on pupils’ parental education suggests that school meals can play a role in compensating for poorer dietary quality in the home environment.

Study II aimed to develop a holistic linear optimization strategy for achieving a sustainable Swedish school food supply. The developed strategy reduced greenhouse gas emissions (GHGE) from the school food supply by 40% with only small changes to the observed supply while also ensuring nutritional adequacy and affordability. Cost was reduced or comparable to baseline in all modeled solutions. Constraints applied to achieve higher levels of similarity to the observed supply prevented the linear optimization model’s capacity to reduce GHGE.

Study III combined the optimization strategy developed in Study II with meal planning to design a sustainable 4-week lunch menu, which was tested in a school-based intervention study. Pre-post analyses evaluated the acceptability of the new menu by assessing effects changes to food waste, pupils’ school lunch consumption, and their satisfaction with school meals. The new menu was introduced in three Swedish primary schools (grades 0-9) without increasing food waste or change pupils’ consumption of, or satisfaction with, the school lunch.

Study IV qualitatively evaluated the acceptability of the new sustainable school lunch menu. Focus group discussions explored pupils’ and kitchen staff’s experiences with the new menu as well as potential barriers and facilitators to successful implementation of sustainable school meals at scale. Experiences with the intervention varied among pupils and kitchen staff. Barriers included pupils’ unfamiliarity with eating plant-based meals and the lack of financial resources, adequate equipment and time for kitchen staff to prepare such meals. Aspects such as increased exposure to plant-based foods, knowledge, motivation, and stakeholder involvement were seen as facilitators to successful implementation.

The findings of this thesis highlight how integrated methods and actions implemented in the school meal system could help to foster sustainable dietary habits in children and thus contribute to meeting the needs of both human and planetary health.