Designing healthy, climate friendly and affordable school lunches

Abstract

Ribal Sanchis, FJ.; Fenollosa Ribera, ML.; García Segovia, P.; Clemente Polo, G.; Escobar Lanzuela, N.; Sanjuán Pellicer, MN. (2016) Methods: An optimizing technique, specifically integer goal programming, is used as a means of designing diets which take into account the aforementioned aspects. Goal programming (GP) is used to design those menus that meet, or nearly meet, all the requirements with respect to caloric content, caloric share among macronutrients, nutrients to encourage and nutrients to limit, while reducing the carbon footprint (CFP) and the lunch budget. In order to have real, acceptable dishes, a school catering company provided information about the typical dishes they serve. The CFP of each dish was assessed, based on literature about life cycle assessment and CFP studies on food products. The nutritional value of each dish was obtained from databases, whereas prices were gathered from a wholesaler. Results and discussion:After solving the goal programming model for several CFP and budget goals, the results show reductions with respect to the average CFP of between -13% and -24%, and reductions with respect to the average budget between -10% and -15% while maintaining the nutritional aspects similar to the average of the proposed menus. The results show that a wide range of budget is available, maintaining an almost constant CFP and meeting nutritional requirements to a similar degree; therefore, it is possible to avoid trade-offs between the CFP and the budget. The analysis of the dishes selected shows how the optimization model, in general, avoids the dishes which have a high CFP and high price and which are low in iron content, but high in protein and cholesterol. Conclusions:Goal programming constitutes a suitable tool for designing diets which are economically, environmentally and nutritionally sustainable. Its flexibility enables specific issues to be studied, such as the existence of possible trade-offs between budget and CFP, attained by changing the budget and the CFP goals. By means of an iterative process, new dishes could be introduced or the existing ones could be improved, thus providing catering companies with useful information.

EATS: a life cycle-based decision support tool for local authorities and school caterers

“…Nevertheless, the analysis presented here only focuses on the environmental impact of school meals. It is important to recognise that the main drivers in the design of school menus are nutritional considerations and costs (Ribal et al 2016). To achieve a holistic assessment, additional considerations need to be made to enable an evaluation of the synergies and tradeoffs between the provision of economically sustainable, healthy and low-impact meals.…”

“…Benvenuti et al (2016) used a life cycle assessment (LCA)based approach to assess menus served in public schools in Rome and to design optimised menus with low environmental impact (in terms of water consumption and greenhouse gas emissions) and that ensure the correct energy and nutrients intake. A similar approach was adopted by Ribal et al (2016), who calculated the greenhouse gas emissions of a set of dishes served by a school caterer in Spain, basing their results on secondary data from LCA studies. Based on this, they developed an optimisation algorithm to generate menus that responded to a set of nutritional, environmental and economic requirements.…”

Environmental impacts of food consumption and nutrition: where are we and what is next?

“…Other aspects such as taste, attractiveness, and price were more important decision criteria for customers than the carbon footprint. Ribal et al (2015) describe an optimization model (goal programming), which was used to design meals for school canteens by taking into account nutritional, climate change, and economic aspects. Reductions in carbon footprints and prices of meals were possible while maintaining the nutritional properties of the meals.…”

Concurrent economic and environmental impacts of food consumption: are low emissions diets affordable?

“…Moreover, in the present work, two conflicting priorities are considered, that is the GHGE and the price of the menu so that a multi-objective optimization problem has to be solved considering the trade-off between these conflicting objectives. A similar approach, that is 0-1 integer linear programming problem, is proposed in (Ribal et al, 2016) but a single meal per day and a very small number of recipes are considered, so that acceptability constraints result to be very basic. Moreover, nutritional constraints are considered only over the entire menu thus resulting unrealistic from nutritionists' point of view.…”