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

Sustainability of food consumption concerns both environmental and economic issues. In fact, the United Nations Food and Agricultural Organization defines as sustainable diets those that are protective and respectful of ecosystems, culturally acceptable, economically affordable, besides ensuring an adequate and healthy nutrition. In this paper, a systematic methodology to plan menus complying with nutritional and health issues, close to current eating habits, affordable and with low greenhouse gas emissions is presented. The methodology relies on a multi-objective optimization model with binary variables. The objectives, that is the greenhouse gas emissions needed to serve the menu and its price, are conflicting and therefore a trade-off has to be established by means of the set of Pareto solutions. Any such a solution delivers a menu in term of the recipes composing each daily meal. The application of the presented methodology to the case of cycle menus for nursing homes is investigated. The case study shows that the menu's environmental impact is generally in inverse proportion to its price. Nevertheless, it is possible to obtain a menu with a significantly reduced environmental impact at an affordable extra cost. (C) 2019 Elsevier Ltd. All rights reserved.