Air quality and diet preference: do consumers purchase more healthy food when breathing polluted air?

PurposeThis research examines how air quality, as a direct environmental factor, impacts individual food choices.Design/methodology/approachStudy 1 uses a panel of more than ten thousand people with one-year shopping records to examine the relationship between air quality and healthy food purchase. Study 2 employs a scenario-based experiment to investigate the underlying behavioral mechanisms regarding food consumption as individual response to mitigate perceived stress caused by air pollution.FindingsUsing data from a major Chinese supermarket chain in a large city, combined with daily local air quality measurements over a one-year period, Study 1 revealed a nonlinear relationship between air quality and healthy food purchases. Specifically, as air quality deteriorates to moderate levels, healthy food purchases decrease, reaching the lowest point under medium pollution levels. However, when air pollution becomes severe, healthy food purchases increase again, resulting in a "U-shaped" pattern. In a subsequent scenario-based experiment (Study 2), poor air quality was found to increase individuals' perceived stress, which subsequently influenced food choices. This effect was moderated by the emotion regulation strategies individuals adopted, providing a behavioral explanation for the observed U-shaped relationship.Originality/valueThis research uncovers a nonlinear relationship between air quality and individual healthy food choices. Moreover, it highlights the role of emotion regulation strategy in shaping the effect of air quality on individual behavior.