The Effect of Altering Food Packaging Size on Expected and Perceived Satiation

The purpose of this study was to investigate the effect of changing a food’s packaging size on the perceived weight, expected satiation prior to eating, and perceived satiation after eating of that food. It was hypothesised that a smaller bag would be perceived to be heavier (in accordance with the size-weight illusion, SWI), and would be expected and perceived to be more satiating. Participants (N=51) were presented with a large and a small foil bag with the same amount of food inside. They provided ratings of how heavy they perceived each bag to be, how much they expected each bag to fill them up, and how full they felt after eating each bag. Results showed that the smaller bag was perceived to be heavier (p = .001), confirming that the SWI had occurred. The difference in packaging size was not found to have a statistically significant effect on expected or perceived satiation (p > .05 in both cases). It was concluded that changing a food’s packaging size can affect our perception of the food’s weight, but not satiation.