Seeing Smaller Portions Creates New Normal
Reducing food portion sizes may shift a person’s perceptions of what is a normal amount of food to eat and induce them to choose smaller portions next time, suggests a study in the American Journal of Clinical Nutrition. Researchers recruited participants for the study from staff and students at the University of Liverpool, UK, to participate in a series of three laboratory experiments lasting up to a week.
In the first experiment, female diners were randomly assigned to receive one of two portions (large or small) of quiche for lunch. The next day, the participants returned and were invited to serve themselves whatever portion they desired; those who had been served the smaller portion the day before tended to choose smaller portions. The second experiment tested male diners instead of female diners, and found the same results.
Finally, in the third experiment, both male and female diners were included, but this time they were assessed a week after the initial lunch. Researchers administered a visual questionnaire to gauge what portion sizes looked “normal” to the participants. Diners previously served smaller portions rated the smaller portions on the questionnaire as more normal. All three experiments pointed to the idea that being served smaller portions can shift perceptions of what is the “right” amount of food to eat, even up to a week later. The researchers noted that downsizing portions of commercially packaged foods could hypothetically alter public perceptions enough to counter the phenomenon of “portion distortion” that may fuel high obesity rates.