Promoting healthy choices from vending machines: Effectiveness and consumer evaluations of four types of interventions

•Restricting high-calorie options in vending machines stimulates healthier choices.•Intrusiveness of interventions does not necessarily lower acceptance.•Interventions are accepted more when they are experienced in a realistic setting.•Satisfaction with choices and frustration when making choices do not differ between intervention types. Vending machines often provide relatively energy-dense snack foods and beverages at a wide variety of points-of-purchase. Vending-machine interventions that stimulate low-calorie choices can therefore play a role in improving the healthfulness of the food environment landscape. The aim of this study is to examine the effects of four vending-machine interventions, varying in level of intrusiveness, on consumers’ choices, consumers’ acceptance of such interventions, and consumers’ evaluations of the choice they made. In a between-subjects design experiment (N = 206), respondents were asked to purchase a snack and a beverage from a vending machine. In addition to a no-intervention condition, four types of incrementally intrusive interventions were implemented: calorie labelling, increasing accessibility of low-calorie choices, increasing prices of high-calorie choices, and restricting availability of high-calorie choices. A post-choice questionnaire included items concerning intervention acceptance, and assortment and choice evaluations. Compared to the no-intervention condition, the most intrusive intervention (i.e. restricting availability of high-calorie choices) led to more low-calorie choices (39% vs. 78%), while less intrusive interventions (i.e. calorie labelling, increasing accessibility of low-calorie choices, and increasing prices of high-calorie choices) did not. Intervention acceptance and choice evaluations were equally high across the four intervention types. Overall, the results suggest that restricting high-calorie options is a promising route to stimulate healthier choices from vending machines. As such, the present study provides intervention opportunities in the combat against obesity for governments and their potential allies, such as food manufacturers and the food service industry.