The “healthy = sustainable” heuristic: Do meal or individual characteristics affect the association between perceived sustainability and healthiness of meals?

Research has found an association between the perceived sustainability and healthiness of foods and meals between individual consumers. The current study aimed to investigate whether the association between perceived sustainability and healthiness on the individual level is rooted in reality. Moreover, we investigated whether meal or individual characteristics affect this association. In total, 5021 customers of a public canteen rated the sustainability and healthiness of 29 meal options. For determining the actual environmental sustainability and healthiness scores, exact recipes of each meal were analyzed using the NAHGAST algorithm. Results showed a substantial association between perceived sustainability and healthiness at the individual level. However, this perceived relation was unrelated to the overlap between the actual environmental sustainability and healthiness scores of the meals. Moreover, this “healthier = more sustainable” perception was unrelated to other meal characteristics (e.g., vegan content) or individual characteristics (i.e., gender, eating style). However, this association was slightly higher in older than in younger participants. The present study shows in a real-world setting that food consumers seem to evaluate the sustainability and healthiness of meals based on a simple “healthy = sustainable” heuristic which is largely independent of the actual overlap of these dimensions. Future research is needed to shed more light on the nature, sources, and consequences of this heuristic.Author summary: Eating healthy and sustainable diets is a major challenge of our time; important but often not achieved. In the present study, we investigate the perceived sustainability and healthiness of foods, an important factor in choosing sustainable and healthy diets. In a real-world canteen setting, we asked consumers to rate the sustainability and healthiness of their consumed meals. Results show that respondents seem to rely on a “healthy = sustainable” heuristic. Specifically, if respondents perceived a meal as healthier, they also perceived it as more sustainable. This association was comparable between meals that had highly similar actual environmental sustainability and healthiness scores and meals that had very dissimilar actual scores. These results imply that it might be necessary to provide consumers with information regarding both the environmental sustainability and healthiness of foods to underline that these two dimensions can differ. Thus, one way forward might be the introduction of a sustainability label on foods, next to a healthiness label which already has been implemented in many countries.