Augmented Reality (AR) - a technology that integrates 3D virtual objects into a real environment in realtime - has recently gained a lot of attention and is expected to become a 100 billion dollar industry by 2023. Surprisingly, researchers present a different picture of AR. They wonder about the functional benefits of AR and the impact of AR applications on customer engagement and buying behavior. There is also a striking lack of empirical evidence. This study aims to close these gaps by being one of the first field experiments in which the impact of AR on user engagement and order value is measured in a live environment. The live environment chosen for this study was a restaurant, as restaurants have been found to engineer their menu to affect order value - so an AR menu with 3D virtual dishes could be developed to manipulate the behavior of participants in the restaurant. The participants found the AR menu to be more representative of the dishes and their portion sizes compared to the regular, paper menu. Unfortunately, this did not translate into an increased order value or NPS score. Second, it was found that Perceived Usability - a dimension of user engagement - had a direct, positive impact on order value in the mediation model presented in this study. With these findings this study provides empirical support for what has been found in user engagement and AR theory. Future studies can further explore this relationship and more interestingly, businesses and researchers can use AR and data analytics to optimize and learn from our relationship with food.