Curbing portion size effects by adding smaller portions at the point of purchase

Point of purchase interventions may curb portion size effects and overconsumption by consumers. This study determines whether adding smaller portion sizes to a retailer's assortment unobtrusively encourages consumers to buy smaller portions. Therefore, a field experiment with meat sausage as focal product, was conducted over the course of a month in a branch of a large European retailer, generating receipts of each individual shopping trip. The product sales data revealed slightly more sales of the two smaller portions in terms of units (52%), versus the default, larger portion (48%), resulting in a pertinent reduction in total volumes sold in kg. Furthermore, a two-way ANOVA comparing sales at the individual level before and during the intervention for the experimental store versus eight control stores showed a reduction in the volume of meat sold during the intervention period in the experimental store. Moreover, the results of a one-way ANOVA indicated that smaller portion buyers do not compensate by buying more other products within the same product category. The finding that adding smaller portions to a default choice architecture can nudge consumers towards buying smaller sized items, has important implications for retailers and public policy makers involved in promoting healthy and sustainable consumer behavior.