Exploring the role of Effort within the Proximity Effect: A Study Protocol

Obesity prevalence is increasing around the globe, with interventions manipulating the decision environment thought to have a large potential to change behaviour. One such simple yet effective intervention utilises the Proximity Effect, whereby snack consumption is decreased as the physical distance (proximity) between the individual and the snack is increased. Recent studies have suggested that visual salience and physical effort may underpin the effect. The current protocol outlines the first study to experimentally manipulate effort to determine its potential role in the proximity effect. A sample of 90 university students will be randomly allocated to one of four conditions in a 2 (proximity; 20cm vs 70cm) x 2 (effort; unwrapped vs wrapped) between subjects study. Twenty chocolate brownies will be presented at either 20cm or 70cm, with these brownies being either unwrapped or wrapped in a single layer of clear plastic film (high effort). Participants will also complete self-report measures for potential moderating factors including eating behaviour and perceived visual salience.Primary outcomes of the study are likelihood of consumption (whether an individual consumed any of the snack), and the actual amount consumed (kCal) according to experimental conditions. Implications of the results may be implemented in food service areas to decrease consumption of unhealthy foods by increasing the physical effort required to attain such foods.