A two-phase optimization approach in designing sustainable hospital menus by integrating nutrition, cost, and environmental factors.

The current pattern of food production and consumption in the world has put great pressure on the environment, so a shift towards sustainable diets seems more urgent than ever. Within this context, organizations such as hospitals offer valuable opportunities to promote sustainable eating practices. The aim of the present study is to design a menu that minimizes environmental impact and cost, while simultaneously maximizing nutrient-rich food (NRF). A two-phase linear optimization was conducted at Imam Reza Hospital, Mashhad, Iran, combining linear and goal programming to optimize the quantities of each food. In this regard, data on recipes, quantities, and prices were collected over a 461-day period in the hospital canteen. For each meal, NRF, water footprint, carbon footprint, and cost were calculated. Four different scenarios were developed, and the best scenario was used to design one-year meal plans that meet macronutrient targets for protein, fat, and carbohydrates, and maintain dietary variety. The optimized menu attained a 36% reduction in carbon footprint and a 42% reduction in water footprint, while enhancing NRF by 10% and reducing cost by 42% in comparison with the prevailing menu. The mean percentage change in fat and carbohydrates from the obtained menu was -7.5% and 6%, respectively, which ensured the mean percentage change in all macronutrient levels aligns with recommended guidelines. The results of this study showed that healthier menus can be designed with a smaller environmental footprint, while maintaining or even significantly reducing costs.