Portion size is known to be a key driver of food intake. As consumed portions are often pre-planned, ‘ideal portion size’—an individual’s preferred meal size selected prior to eating—has been identified as a strong predictor of actual consumption. However, assessments of ideal portion size have predominantly relied on laboratory-based computer tasks, limiting use online. Therefore, this cross-sectional study sought to pilot test the validity of a web-based tool to measure ideal portion size. In an online study (N = 48), participants responded to images of a range of foods. Each food was photographed in a series of different portions and loaded into an ‘image carousel’ that would allow participants to change the size of the displayed portion by moving a slider left-to-right. Using this image carousel, participants selected their ideal portion size. They also completed measures of expected satiety and expected satiation and self-reported their age and body mass index (BMI). A non-parametric correlation matrix was used to explore associations between ideal portion size and identified predictors of food intake. Supporting convergent validity of this measure, ideal portion size was significantly correlated with expected satiety (rs = .480) and expected satiation (rs = −.310) after controlling for effects of baseline hunger and fullness, consistent with past research. Similarly, supporting divergent validity of this measure, ideal portion size was not significantly correlated with age (rs = −.032) or BMI (rs = −.111,). Pilot results support the validity of this web-based portion size selection tool used to measure ideal portion size, though further research is needed to validate use with comparisons to actual food intake.

中文翻译：

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测试份量选择的在线测量：一项关于理想份量测量的试点研究

众所周知，份量是食物摄入的关键驱动因素。由于食用份量通常是预先计划好的，因此“理想份量”——个人在进食前选择的首选膳食量——已被确定为实际消费量的有力预测因素。然而，理想份量的评估主要依赖于基于实验室的计算机任务，限制了在线使用。因此，这项横断面研究试图对基于网络的工具测量理想份量的有效性进行试点测试。在一项在线研究 (N = 48) 中，参与者对一系列食物的图像做出反应。每种食物都被分成一系列不同的部分拍摄并加载到“图像轮播”中，参与者可以通过从左到右移动滑块来更改显示部分的大小。使用此图像轮播，参与者选择了他们理想的份量。他们还完成了预期饱腹感和预期饱腹感的测量，并自我报告了他们的年龄和体重指数 (BMI)。使用非参数相关矩阵来探索理想份量与确定的食物摄入量预测因子之间的关联。支持该测量的收敛效度，在控制基线饥饿和饱腹感的影响后，理想份量与预期饱腹感 (rs = .480) 和预期饱腹感 (rs = -.310) 显着相关，这与过去的研究一致。同样，支持该测量的发散效度，理想的份量与年龄（rs = -.032）或BMI（rs = -.111，）没有显着相关性。试点结果支持这种基于网络的份量选择工具的有效性，用于测量理想份量，