Immersive Virtual Reality Dietitian Improves Portion Control Self-Efficacy and Portion Size Estimation Accuracy

Objective: To compare the impact of a nutrition education program delivered in person and within an immersive virtual reality (iVR) nutrition education experience application called immersive virtual alimentation and nutrition (IVAN). To compare IVAN with its updated version, IVAN 2, and develop a portion size estimation task for use within iVR. Design: Two randomized controlled experiments. Setting: Laboratory. Participants: Ninety-two adults (aged 29 ± 14) years) enrolled. In experiment 1, 25 adults were randomized to in-person and 20 to the IVAN condition. In experiment 2, 25 adults were randomized to IVAN 1, and 22 adults were randomized to IVAN 2 conditions. Intervention: Nutrition education materials delivered in person by IVAN 1 and IVAN 2. Main Outcome Measures: Changes in portion control self-efficacy and portion-size overestimation. Analysis: Linear mixed-effects models and t tests. Results: In experiment 1, the portion size self-efficacy improved for both conditions (B = 2.40; SE = 0.61; P <0.001) with no difference between conditions. In experiment 2, the portion size self-efficacy improved for both conditions (B = 1.23; SE = 0.55; P = 0.03), as did the portion-size overestimation value (B = −21.51; SE = 4.97; P <0.001), with no difference between conditions. Conclusions and Implications: Portion-size education material shows similar efficacy delivered through IVAN and in person. The efficacy of IVAN 2 was higher than IVAN 1. Portion size estimation tasks within iVR may be useful for the assessment of participants’ ability to estimate portion sizes.