The effect of unit portion size and food weight cues on visual and tactile intended consumption assessments

Abstract

Obesity is a global health issue and one of the leading causes of chronic disease. In the current food environment, portion size is a key factor contributing to obesity, as its increase leads to a corresponding rise in food intake. This phenomenon is known as the “portion size effect”. Understanding how people estimate their food intake is crucial in combating this issue. People typically estimate their intake based on food portion sizes before eating, and this intended consumption closely correlates with actual intake. Therefore, adjusting the assessment of intended consumption could influence actual intake, moderating the portion size effect. This study investigated the impact of unit portion size and weight cues in evaluating intended consumption through visual and tactile assessments. Thirty-two participants completed 48 assessments by viewing food images in a visual task, and another 48 assessments by touching foods in a tactile task. The results indicated that intended consumption was greater for large unit portion sizes in both visual and tactile tasks. However, when participants were provided with food weight cues, their intended consumption increased for smaller portion sizes and decreased for larger portion sizes, partially mitigating the portion size effect. In addition, there are differences between visual and tactile assessment modalities, with higher intended consumption in the tactile assessment task. This study revealed that both weight cues and sensory models could influence intended consumption, and these should be further used to promote healthy eating.