High satiety expectations of a first course promote selection of less energy in a main course picture task

One of the factors determining meal size is the expectation one has about satiating properties of foods. Foods eliciting low satiety expectations are often chosen in larger portions. We investigated whether satiety expectations of one food lead to a different portion size selection of other foods, using an online picture task. One hundred and twenty-six subjects (64 unrestrained, 62 restrained) participated in three conditions (within-subject). In two conditions subjects were asked to imagine they consumed soup as a first course. They were shown pictures of soups differing in terms of visual attributes, e.g. colour intensity, ingredients variety, etc. that conveyed a high or low expected satiety. In the control condition, no picture was shown. After viewing either a soup picture or no picture, subjects chose an ideal menu and portion size out of several other foods (meat, side dishes and vegetables) via an online choice task, specifically developed for this experiment. The energy (kcal) and weight (grams) selected for the main course was measured. More energy was chosen in the low satiety compared with the high satiety soup picture condition, but this effect was only significant for restrained eaters. This study shows that satiety expectations of a first course 'carry over' to the rest of the menu in people who carefully watch their diet, i.e. restrained eaters make satiety estimations for an entire menu. Our online choice task was able to capture these estimations in an implicit manner.