Development of a Simplified Portion Size Selection Task

Abstract

Portion size is an important determinant of energy intake and the development of easy to use and valid tools for measuring portion size are required. Standard measures, such as ad libitum designs and currently available computerized portion selection tasks (PSTs), have several limitations including only being able to capture responses to a limited number of foods, requiring participants’ physical presence and logistical/technical demands. The objective of the current study was to develop and test robust and valid measures of portion size that can be readily prepared by researchers and be reliably utilized for remote online data collection. We developed and tested two simplified PSTs that could be utilized online: (1) portion size images presented simultaneously along a horizontal continuum slider and (2) multiple-choice images presented vertically. One hundred and fifty participants (M = 21.35 years old) completed both simplified PSTs, a standard computerized PST and a series of questionnaires of variables associated with portion size (e.g., hunger, food item characteristics, Three Factor Eating Questionnaire). We found average liking of foods was a significant predictor of all three tasks and cognitive restraint also predicted the two simplified PSTs. We also found significant agreement between the standard PST and estimated portion sizes derived from the simplified PSTs when accounting for average liking. Overall, we show that simplified versions of the standard PST can be used online as an analogue of estimating ideal portion size.

Gender, Age, Hunger, and Body Mass Index as Factors Influencing Portion Size Estimation and Ideal Portion Sizes

“…In our study, in order to increase participation, we did not restrict screen parameters but we specified picture size for all types of screens. Also, various types of online surveys are used to estimate portion sizes ( Embling et al, 2021 ; Pink and Cheon, 2021 ). However, when compared, for example, simplified and standard portion selection task forms both results in comparable results and can be used online to estimate ideal portion size ( Pink and Cheon, 2021 ).…”

Testing an online measure of portion size selection: a pilot study concerned with the measurement of ideal portion size

“…However, to our knowledge, current tasks cannot be used remotely as part of a web-based survey. One recent study found some evidence of agreement between a standard computer-based assessment of portion size and a 'simplified' portion selection task that could be used online (with 5-7 portion size images loaded into a horizontal slider and vertical Likert scale), but such tasks may be limited in terms of the variability in portion size that can be displayed to participants [29]. For instance, in a previous online study, we asked participants to scroll through a large selection of portion size photographs as part of a Likert-scale type measure, but noted that functionality and the 'animated' presentation of portion sizes from a computer-based task were lost, predominantly due to a need to present smaller-scale images simultaneously rather than consecutively onscreen [22].…”