Optimizing School Food Supply: Integrating Environmental, Health, Economic, and Cultural Dimensions of Diet Sustainability with Linear Programming

• Published in: International journal of environmental research and public health 2019, Vol.16 (17), p.3019
• Main Authors: Eustachio Colombo, Patricia, Patterson, Emma, Schäfer Elinder, Liselotte, Lindroos, Anna Karin, Sonesson, Ulf, Darmon, Nicole, Parlesak, Alexandr
• Format: Article
• Language: English
• Subjects: Agenda 2030; Anthropogenic factors; Biodiversity; Carbon dioxide; carbon footprint; Cardiovascular diseases; catering service; children; choices; Climate change; contribute; cost constraint; Costs and Cost Analysis; Cultural factors; Culture; Diabetes mellitus; Diet; Emissions; Energy; energy density; Energy Intake; Environmental & Occupational; environmental health; Environmental Sciences & Ecology; Food; Food and Nutrition; Food processing; Food supply; Food Supply - economics; Food waste; Greenhouse effect; Greenhouse Effect - prevention & control; greenhouse gas emissions; Greenhouse Gases; Health; high nutritional quality; Human influences; Humans; impact; Legumes; Life Sciences; Linear programming; Meals; meat; Medicin och hälsovetenskap; Models, Theoretical; Morbidity; Nutrient content; nutrition; Nutrition and Dietetics; Nutrition Policy - economics; Näringslära; Plant-based foods; Programming, Linear; Public; Santé publique et épidémiologie; school meals; Schools; Schools - economics; self-selected diets; Sustainability; Sustainable development; Sustainable food system; Sweden; system analysis; Urbanization; vegetarian
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph16173019

There is great potential for reducing greenhouse gas emissions (GHGE) from public-sector meals. This paper aimed to develop a strategy for reducing GHGE in the Swedish school food supply while ensuring nutritional adequacy, affordability, and cultural acceptability. Amounts, prices and GHGE-values for all foods and drinks supplied to three schools over one year were gathered. The amounts were optimized by linear programming. Four nutritionally adequate models were developed: Model 1 minimized GHGE while constraining the relative deviation (RD) from the observed food supply, Model 2 minimized total RD while imposing stepwise GHGE reductions, Model 3 additionally constrained RD for individual foods to an upper and lower limit, and Model 4 further controlled how pair-wise ratios of 15 food groups could deviate. Models 1 and 2 reduced GHGE by up to 95% but omitted entire food categories or increased the supply of some individual foods by more than 800% and were deemed unfeasible. Model 3 reduced GHGE by up to 60%, excluded no foods, avoided high RDs of individual foods, but resulted in large changes in food-group ratios. Model 4 limited the changes in food-group ratios but resulted in a higher number of foods deviating from the observed supply and limited the potential of reducing GHGE in one school to 20%. Cost was reduced in almost all solutions. An omnivorous, nutritionally adequate, and affordable school food supply with considerably lower GHGE is achievable with moderate changes to the observed food supply; i.e., with Models 3 and 4. Trade-offs will always have to be made between achieving GHGE reductions and preserving similarity to the current supply.