Downsizing by design – Investigating acceptance, choice and willingness to pay for portion control design concepts

Nudge theory predicts that consumers will select smaller portions of high energy density (HED) foods and drinks when packaging presents physical or other limits. To test the feasibility and acceptability of packaging concepts designed to limit portion sizes for children, two mixed methods studies were conducted. Packaging with functional serving size reminders, visual narrative, and metaphor were developed using 3-D prototypes. In each study, packaging prototypes were assessed, either in person (Study 1, n = 50) or via an online survey (Study 2, n = 297). In Study 1, parents visiting a Science museum poured servings for their children of HED foods/drinks and provided feedback on prototypes designed to limit portions of these items. Responses were recorded via questionnaire and interview. In Study 1, parents significantly adjusted amount poured for children based on age and in alignment with recommended portion sizes; they reported that the packaging prototypes would facilitate portion control through education, convenience and autonomy but raised concerns about costs and recyclable/reusable materials. In Study 2 parents responded to the same prototypes online providing measures of willingness to pay (WTP), forced choice and open-ended feedback for each concept. Parents were WTP more for downsizing packaging concepts, choosing them over their regular brand in most cases and confirming a generally positive view of the designs. However, WTP magnitude depended on consumer segmentation (price concerns, health motives). Innovative design concepts can be used to nudge towards smaller portions, but this depends on parental motivation.