Optimat - research project about optimizing and improving school meals

The Swedish school meal scheme offers a unique opportunity to foster healthy and sustainable dietary habits among the younger generation. This 4-year research project started in October 2016. It is led by researchers at Karolinska Institutet and is financed by the Swedish Research Council Formas.

Children standing in line for school lunch
Children standing in line for school lunch. Photo: iStock. Photo: istock

The aim of the project is to develop a holistic model for designing health-promoting, affordable, and socially acceptable school meal plans optimized for environmental sustainability (greenhouse gas emissions) and to test the applicability in practice.

OPTIMAT was chosen by the Royal Swedish Academy of Engineering Sciences as one of 100 innovative research projects with a sustainability focus and business potential

Background to OPTIMAT

The food system is responsible for 25-30% of total greenhouse gas emissions (GHGE), a figure which needs to be reduced significantly in order to mitigate climate change. Furthermore, unhealthy diets contribute significantly to the global burden of disease by increasing risks for cardiovascular diseases, obesity, cancers and type-2 diabetes. The adoption of healthy and sustainable diets, in conjunction with a reduction in food loss and waste presents major opportunities for simultaneously reducing the climate impact from food systems and improving health outcomes.

Public procurement of food for e.g. school meals has the potential to change demand, and thereby the food produced and consumed, in the short and long term. Fully subsidized school lunches are served daily in Swedish primary schools to all 1.3 million children aged 6 to 15. Thus, improved school meals have considerable potential to shape children’s diets and reduce food related GHGE.

Planning of school meals is challenging and must take many aspects into account: the food must be healthy, have a low environmental impact, be appealing to the pupils and be affordable on tight budget.

One method to meet these demands simultaneously is through linear optimization. In OPTIMAT, food purchasing lists (i.e. all foods purchased in a given time period) are optimized using linear programming. From the optimized list of the same foods but in new proportions, a new meal plan can be produced by an experienced meal planner.

The overall OPTIMAT project also includes an updated assessment of the contribution that school meals make to children’s total diets today in a national sample of school children.


1. Assessment of the contribution that school meals make to children’s total diet today and if this contribution differs between socioeconomic groups among a representative sample of 2002 Swedish school children (Riksmaten ungdom). STATUS: Published in Public Health Nutrition 2020 (find under "Publications")

2. A new module in the national instrument for following up school meal quality SkolmatSverige to monitor lunch consumption and food waste at school and municipality. STATUS: launched 1 August 2019. 

3. A methodological paper describing how to use linear programming for developing an appropriate strategy to reduce GHGE in the Swedish school food supply, without compromising its nutritional adequacy, affordability, and cultural acceptability. STATUS September 2019 – published in International Journal of Environmental Research and Public Health (see below)

4. Sustainable and acceptable school meals through optimization analysis: an intervention study. Manuscript under review.

5. Interviews with students and kitchen staff in order to explore their views on sustainability and willingness to be part of a sustainable solution for the school meal sector.  STATUS July 2019 - interviews from the three intervention schools have been performed. Analysis will start in September 2019

6. Popular science description of the project and its results 

PhD student Patricia about the OPTIMAT project and Agenda 2030

The sustainable development goals (SDGs) are a collection of 17 global goals set by the United Nations General Assembly in 2015 for the year 2030. 

Other participants in the film are PhD students Anders Klingberg och Juliet Aweko. 

A collaborative project

The project constitutes collaboration between the hosting university Karolinska Institutet, the National Food Agency, and the University College, Copenhagen.


Successful Implementation of Climate-Friendly, Nutritious, and Acceptable School Meals in Practice: The OPTIMAT™ Intervention Study. Sustainability 2020, 12, 8475. Elinder, L.S.; Eustachio Colombo, P.; Patterson, E.; Parlesak, A.; Lindroos, A.K.

Sustainable and acceptable school meals through optimization analysis: an intervention study. Eustachio Colombo P, Patterson E, Lindroos AK, Parlesak A, Elinder LS. Nutrition Journal volume 19, 2020.

The importance of school lunches to the overall dietary intake of children in Sweden: a nationally representative study.
Eustachio Colombo P, Patterson E, Elinder LS, Lindroos AK
Public Health Nutr 2020 Apr;():1-11

Fostering sustainable dietary habits through optimized school meals in Sweden–OPTIMAT (2018). Eustachio Colombo P, Elinder LS, Parlesak A, Lindroos AK, Patterson E. WHO PANORAMA, 557 

Optimising school food supply: integrating environmental, health, economic, and cultural dimensions of diet sustainability with linear programming. Eustachio Colombo P, Patterson E, Elinder LS, Lindroos AK, Sonesson U, Darmon N, Parlesak A. International Journal of Environmental Research and Public Health (2019).


Liselotte Schäfer Elinder

Adjunct professor in Public Health

Liselotte Schäfer Elinder (PI) is adjunct professor in Public Health Sciences at the Department of Global Public Health, Karolinska Institutet, and leader of the research group “Community nutrition and physical activity”.  She is also employed at the Centre for Epidemiology and Community Medicine, Region Stockholm.

ORCID: orcid.org/0000-0001-7270-1162

Profile page at ki.se

Patricia Eustachio Colombo

PhD student

Patricia Eustachio Colombo is a PhD student at the Department of Global Public Health, Karolinska Institutet and plans to defend her thesis in spring 2021.

ORCID: orcid.org/0000-0002-8505-116X

Emma Patterson


Emma Patterson (PhD) is a researcher at the Department of Global Public Health, Karolinska Institutet and also employed at the Centre for Epidemiology and Social Medicine at Region Stockholm where she is responsible for SkolmatSverige.

ORCID: orcid.org/0000-0003-1208-0936

Anna Karin Lindroos

Risk and benefit assessor

Anna Karin Lindroos (PhD) is Risk and benefit assessor at the National Food Agency in Sweden. She is also adjunct senior lecturer at the Department of Internal Medicine and Clinical Nutrition, the Sahlgrenska Academy, University of Gothenburg.

ORCID: orcid.org/0000-0002-4748-4300

Alexandr Parlesak

Associate Professor

Alexandr Parlesak (PhD, Dr. habil.) works as Associate Professor at the Global Nutrition and Health Department, University College Copenhagen, Denmark.

ORCID: orcid.org/0000-0002-8973-3467