School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW, 2006, Australia.
Charles Perkins Centre, The University of Sydney, Sydney, NSW, 2006, Australia.
Eur J Clin Nutr. 2023 Aug;77(8):815-822. doi: 10.1038/s41430-023-01290-y. Epub 2023 May 22.
Perceived portion size norms (typical perception of how much of a given food individuals choose to eat at a single occasion) may have shifted towards larger sizes due to the ubiquity of large serving sizes. However, there is a lack of validated tools to assess such norms for energy-dense and nutrient-poor discretionary foods. This study aimed to develop and validate an online tool to examine the perceived portion size norms of discretionary foods.
An online image-series tool of 15 commonly consumed discretionary foods was developed, with eight successive portion size options included for each food. Using a randomised-crossover design, adult consumers (18-65 years) completed the validation study in a laboratory session (April-May 2022) by reporting their perceived portion size norms for each food twice, once based on food images on a computer and another time based on equivalent real food portion size options at food stations in the laboratory. Agreement between methods for each test food was examined using cross-classification and intra-class correlation (ICC).
A sample of 114 subjects were recruited (mean age 24.8 years). Cross-classification indicated >90% of selections were matched in the same or adjacent portion size option. ICC was 0.85 across all foods, demonstrating a good level of agreement.
This novel online image-series tool developed to examine perceived portion size norms of discretionary foods showed good agreement with equivalent real food portion size options and may be valuable to investigate perceived portion size norms of common discretionary foods in future studies.
由于大份量的普遍存在，人们对食物份量的感知标准（个体在单次进食中选择食用某种特定食物的典型份量感知）可能已经向更大份量转变。然而，目前缺乏有效的工具来评估能量密集型和营养贫乏的随意性食物的这些标准。本研究旨在开发和验证一种在线工具，以评估随意性食物的感知份量标准。
开发了一个包含 15 种常见随意性食物的在线图像系列工具，每个食物都包含八个连续的份量选项。采用随机交叉设计，成年消费者（18-65 岁）在实验室环境中（2022 年 4 月至 5 月）完成验证研究，通过两次报告每种食物的感知份量标准来完成，一次基于计算机上的食物图像，另一次基于实验室中食物站的等效真实食物份量选项。使用交叉分类和组内相关系数（ICC）检验每种测试食物两种方法之间的一致性。
共招募了 114 名受试者（平均年龄 24.8 岁）。交叉分类表明，>90%的选择都在相同或相邻的份量选项中匹配。所有食物的 ICC 为 0.85，表明一致性较好。
本研究开发的用于评估随意性食物感知份量标准的新型在线图像系列工具与等效的真实食物份量选项具有良好的一致性，可能有助于在未来研究中调查常见随意性食物的感知份量标准。
