Expectancy versus experience – Comparing Portion-Size-Effect during pre-meal planning and actual intake.
About this resource: Eating more when offered more is known as the Portion-Size-Effect (PSE). However, the influence of food presentation through written descriptions and images on a diner's 'expected intake' and, therefore, the PSE was unknown. This research explores the link between 'expected intake' and PSE by comparing the intended versus actual consumption of 62 participants. Participants initially rated their 'expected intake' (or pre-meal PSE) for three different-sized pasta dishes, after which their actual intake (or actual PSE) was measured at three ad libitum sessions over seven weeks. Results suggest that pre-meal PSE increases linearly with portion size, whereas actual PSE had a smaller incremental effect after the presented portion size exceeded the 'appropriate' range. Related to these results, pre-meal PSE was found to be comparable to actual PSE for moderate portion sizes (600g-400 g) but was significantly stronger than the actual PSE for large portion sizes (800g-600g). Overall, results suggest that portion size can have a stronger influence on meal planning than a diner's actual food intake and show that using food cues during pre-meal planning can considerably influence a diner's expected intake.
Food Waste Innovation authors: Mei Peng and Miranda Mirosa.
Citation: Cahayadi, J., Geng, X., Mirosa, M., & Peng, M. (2019). Expectancy versus experience – Comparing Portion-Size-Effect during pre-meal planning and actual intake. Appetite, 135. https://doi.org/10.1016/j.appet.2019.01.012