In an environment where tasty, convenient, and inexpensive high-calorie foods are present in abundance, consumers in many countries worldwide increasingly struggle to manage their caloric intake. Mainly because of this systematic imbalance between calorie intake and calorie expenditure, currently more than 1.5 billion people are overweight or obese. Strategies that stimulate consumers to choose low- rather than high-calorie food products are therefore seen as indispensable tools, and scholars stress that widespread governmental policy measures should be implemented to enforce lasting improvements in dietary behaviors.
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. We aim 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.
Literature on intervention strategies for healthy food choices brings forward three concepts, as important conditions for both enactment of interventions and long-term intervention effectiveness. First, there needs to be evidence of short-term effectiveness. if there is no indication that interventions lead to the desired behavior in the short term, long-term effectiveness is unlikely. Second, both consumers and food manufacturers ideally accept interventions, because a lack of intervention acceptance potentially may lead to discontinuation or non-enactment of (proposed) policies. Third, interventions should not lead to frustration or dissatisfaction when consumers make food choices, as these negative choice evaluations potentially lead consumers to search for alternative purchase locations in which the intervention has not been implemented.
Summarizing, interventions and their intrusiveness can influence people at a behavioral (short-term effectiveness), cognitive (perceived effectiveness and fairness), and affective level. When we examine the effects of the intrusiveness of vending-machine interventions on consumers’ choices, consumers’ acceptance of such interventions, and consumers’ evaluations of the choice they made this analysis, contributes to the existing vending-machine and food choice literature in three ways:
- First, food choice experiments generally focus on the effectiveness of a single intervention type or they compare the effectiveness of two intervention types, most often that of provision of information versus price (dis). We currently try to implement four-intervention types in food choice literature and differ regarding the level of intrusiveness: calorie labelling, increasing accessibility of healthy choices, increasing prices of unhealthy choices, and restricting availability of unhealthy choices. Implementing interventions with varying levels of intrusiveness levels contributes to a better understanding of the effect of intrusiveness on intervention effectiveness and acceptance.
- Second, we investigated the effect of the level of absoluteness on intervention evaluations. Hereto, vending-machine interventions are either evaluated after they have been experienced and a real food choice is made, or evaluated after they have not been experienced, but have merely been described as a hypothetical possibility on paper
- Lastly, by including choice evaluations the present findings enables investigating the associations between behavioral, cognitive, and affective outcomes of different types of intervention strategies, which to our knowledge is unique in food choice intervention literature. Shedding light on these association aids in anticipating positive and negative outcomes of policy interventions and helps to identify policies that are promising with respect to their behavioral, cognitive, and affective outcomes.