Researchers from the University of Cambridge studied the "meal-recall effect," or how remembering a recent meal can reduce how much food one will later eat. They evaluated the impact of recalling a recent meal in detail or believing it was twice as large and satisfying on their appetite.

Among 151 participants included in the study, they found that seeing a meal as larger as, and more satisfying than it actually was led to 24g fewer biscuits later on, comparable to two biscuits or 122 kcal less. The meal-recollect effect was not produced when recalling the meal in great detail. 

Participants were divided into five groups and given microwave-ready rice, sauce, and a cup of water. They were asked to complete imaginative exercises before a "taste test" of biscuits.

In three groups, participants were asked to either recollect eating their most recent lunch in detail or think that it was twice as large and filling as it actually was. In the fourth group, participants were instructed to describe a picture of spaghetti hoops in tomato sauce before picturing moving the meal around a dish. Participants in the fifth group were asked to score the cookies on 12 distinct taste qualities while the experimenters substituted pasta for stationery.

It was seen that the group that pictured spaghetti hoops consumed the most biscuits (75.9g), followed by stationary (75.5g). The group whose meal had been moved around the plate consumed the third-highest amount of biscuits (72.0g). Those who thought their meal would be twice as large consumed the fewest biscuits (51.1g). 

The portion size of the lunch was underestimated by the group, which was instructed to imagine the meal as being twice as big. No impact was observed in other categories.

Experts conclude that deciding how much to eat is sometimes determined by the mind rather than the stomach. More studies are necessary so that people can use the information from these studies to control their overeating and maintain good health.

(Source: https://theprint.in/health/imagining-recent-meal-as-larger-than-reality-might-reduce-snacking-research-2/1426436/)