The Immersive Virtual Alimentation and Nutrition Application: An Interactive Digital Dietitian

Portion size affects food selection in an immersive virtual reality buffet and is related to measured intake in laboratory meals varying in portion size

A crucial step for validating the utility of an immersive virtual reality (iVR) buffet to study eating behavior is to determine whether variations in food characteristics such as portion size (PS) are relevant predictors of food selection in an iVR buffet. We tested whether manipulating PS in an iVR buffet affects the weight of food selected, and whether this response to PS is similar to participants' measured intake when PS varies at laboratory meals. In a randomized crossover design, 91 adults (18-71 y; 64 females; BMI = 25.3 ± 5.7) used their iVR remote to select lunch and dinner portions from an iVR buffet before consuming a standardized lab meal at two visits separated by one week. The PS in the iVR buffet and lab meals varied between a standard PS and a large PS. This design enabled comparisons of PS effects between iVR and lab settings, despite the scale difference in food weight between the environments. Portion size significantly affected food selection and food intake (p < 0.001). Subjects selected an additional 350 g in iVR and consumed an additional 154 g of food in the lab meals when offered the large portion compared to the small portion. The effect of PS showed a similar percentage increase in iVR (36.5%) and lab meals (39.2%). There was no significant difference in the effect of PS between iVR and lab meals after accounting for scale differences in food weight between the environments. The response to PS was not influenced by subject characteristics such as body mass index, sex, or age. These results demonstrate the utility of iVR for replicating real-world eating behaviors and enhancing our understanding of the intricate dynamics of food-related behaviors in a variety of contexts.

The development of an immersive mixed-reality application to improve the ecological validity of eating and sensory behavior research

Introduction

The modern eating environment has been implicated as a driving force of the obesity epidemic. Mixed reality applications may improve traditional methodological assessments of eating behavior by improving the ecological validity of the laboratory setting.

Methods

Research experts evaluated the utility and ecological validity of a mixed reality application that allowed immersion within virtual environments through utilizing the passthrough cameras of the head mounted display to view and interact with real foods. An initial evaluation was conducted that involved three virtual environments: a traditional laboratory booth, a non-textured restaurant, and a full-textured restaurant. The feedback from the initial evaluation was used to create a new virtual restaurant environment and a subsequent evaluation was conducted.

Results

Nearly all research experts suggested adding social cues such as people and background noise to create a more authentic and ecologically valid experience. The experts scored the new virtual restaurant environment to be more acceptable than eating or conducting research in a sensory booth but scored lower when compared to conducting research in a real-world restaurant setting.

Discussion

The results of this evaluation suggest that mixed reality applications may be a new methodology to assess environmental influences of eating behavior and may be a promising direction for eating behavior and sensory science research.

Remote iVR for Nutrition Education: From Design to Evaluation

While different crowdsourcing platforms promote remote data collection, experiments in the immersive Virtual Reality (iVR) research community are predominantly performed in person. The COVID-19 pandemic, however, has forced researchers in different disciplines, including iVR, to seriously consider remote studies. In this paper, we present a remote study using the Immersive Virtual Alimentation and Nutrition (IVAN) application, designed to educate users about food-energy density and portion size control. We report on the results of a remote experiment with 45 users using the IVAN app. In IVAN, users actively construct knowledge about energy density by manipulating virtual food items, and explore the concept of portion size control through hypothesis testing and assembling virtual meals in iVR. To explore the feasibility of conducting remote iVR studies using an interactive health-related application for nutrition education, two conditions were devised (interactive vs. passive). The results demonstrate the feasibility of conducting remote iVR studies using health-related applications. Furthermore, the results also indicate that regardless of level of interactivity learners significantly improved their knowledge about portion size control after using the IVAN (p &lt; 0.0001). Adding interactivity, however, suggests that the perceived learning experience of users could be partially affected. Learners reported significantly higher scores for immediacy of control in the interactive condition compared to those in the passive condition (p &lt; 0.05). This study demonstrates the feasibility of conducting an unsupervised remote iVR experiment using a complex and interactive health-related iVR app.