Imagine this: Visualising a recent meal as bigger reduces subsequent snack intake.

Remembering a recent meal reduces subsequent intake of palatable snacks (i.e. the meal-recall effect), however, little is known about the factors which can potentiate this effect. The present experiment investigated whether a stronger meal-recall effect would be observed if recent consumption would be recalled in greater detail, than if it was recalled briefly. Moreover, it was investigated whether imagining a meal as bigger and more satiating than in reality could potentiate the meal-recall effect, and lead to lower intake. It was also explored whether mental visualisation tasks of a recent meal would affect the remembered portion size. Participants (N = 151) ate lunch at the laboratory, and then returned 3 h later to perform the imagination tasks and to participate in a bogus taste test (during which intake was covertly measured). Participants in the two main imagination task groups recalled the lunch meal and then either recalled the consumption episode in great detail or imagined the meal was larger and more filling than in reality. The results showed that imagining a recent meal as larger significantly reduced the quantity of biscuits eaten. However, contrary to the hypotheses, recalling a consumption episode in detail did not decrease snack intake. It was also shown that imagining a recent meal as larger than in reality did not lead participants to overestimate the true size of the meal. In fact, portion size estimations were significantly underestimated in that group. There were no significant estimation differences in any of the other groups. The results of this study suggest that the meal-recall effect can be an effective strategy to reduce food intake and may be amenable to strategic manipulation to enhance efficacy, but seems prone to disruption.

The role of memory ability, depth and mode of recall in the impact of memory on later consumption.

It has been shown that recalling a meal eaten a few hours earlier (vs. the previous day) leads to reduced snacking ('meal-recall' effect). This study attempted to replicate this effect, by assessing participants' (N = 77, mean age = 33.30 [SD = 14.98], mean BMI = 23.77 [SD = 3.72], 74% female) biscuit consumption during a bogus taste test in two separate sessions, before which participants recalled a recent or a distant meal. It was explored whether factors that might affect the quality of a meal-memory, particularly individual differences in memory ability and depth of recall, would influence the meal-recall effect. To this end, only participants with a low or high memory ability were recruited for the study and were allocated to either an unguided-recall or guided-recall condition. In the unguided condition, participants were asked to recall what they ate, and in the guided condition they were prompted for further details regarding their meal. Participants were asked to either recall their meal out loud through an interview with the experimenter or by writing their recollection down on the computer. Contrary to the initial hypotheses, it was found that only the written group demonstrated the meal-recall effect, whereas the verbal group did not. Moreover, this was specific to the written, unguided group, in which participants ate about 9 g fewer biscuits after recalling a recent (vs. a distant) meal, F (1,15) = 6.07, p = .026, ηp2 = 0.288. The written, guided group's snacking seemed to increase by about 8 g after recalling a recent (vs. a distant) meal, F (1,20) = 7.31, p = .014, ηp2 = 0.268. The meal-recall effect was not evident in the verbal group. Memory ability did not influence the magnitude of the meal-recall effect. The results highlight the importance of contextual factors in modulating the meal-recall effect.