The rise in diet-related non-communicable diseases suggests that consumers find it difficult to make healthy food-related purchases. This situation is most pertinent in fast-paced retail environments where customers are confronted with sugar-rich or savory food items. Countermeasures such as front-of-package labelling are not yet mandated in most regions, and barcode scanning mobile applications are impractical when purchasing groceries. We thus applied a mixed reality (MR) wearable headset-mediated intervention (N = 61) at vending machines to explore the potential of passively activated, pervasive MR food labels in affecting beverage purchasing choices. Through conduction of a betweensubject randomized controlled trial, we find significant, strong improvements in nutritional quality of the selected products (Energy:-34% KJ/100ml, Sugar:-28% g/100ml). Our post-hoc analysis suggests that the intervention effect is especially effective with existing food literacy. This study motivates further research on MR food labels due to the promising, observed intervention effects.