Diet Optimization for Sustainability: INDIGOO, an Innovative Multilevel Model Combining Individual and Population Objectives

Abstract

Diet optimization is a powerful approach for identifying more sustainable diets that simultaneously consider nutritional, economic, cultural, and environmental dimensions. This study aimed to develop an innovative multilevel approach called Individual Diet Including Global Objectives Optimization (INDIGOO) for designing diets that fulfill nutritional requirements and minimize dietary habit shifts at the individual level while attaining environmental impact reduction targets at the population level. For each individual in a representative sample from the French adult population (INCA2 survey 2006–2007; n = 1918), isocaloric and nutritionally adequate optimized diets with minimal shifts from the observed diet were designed. Environmental targets (including a 30% greenhouse gas emissions (GHGEs) reduction) were applied either similarly for each individual (original approach) or at the population level (INDIGOO). Compared with the original approach, INDIGOO enabled smaller dietary changes while distributing the contribution to the overall 30% GHGEs reduction more fairly among individuals (contributions ranging from −69.5% to +64%). For 6.4% of individuals, INDIGOO allowed an increase in GHGEs (+11% on average). Conversely, individuals with the greatest decrease in GHGEs (−45% on average) were characterized by high energy intake and high animal-based products, water, and other beverage consumption. INDIGOO is a promising multilevel approach to support food policy development.