The specially designed nudging tableware promotes healthy food choices: Evidence from a randomized crossover trial in normal-weight young adults

To evaluate the effects of the specially designed nudging tableware, including a plate and bowl, on individual food choices in normal-weight young adults and preliminarily explore its mechanisms. We hypothesized that the toolset could increase the choice of vegetables and decrease that of rice.A randomized, single-blind, two-period crossover trial was carried out among 40 normal-weight university students in China. All subjects completed two buffets separated by an interval of one week, wearing the eye tracker. Vegetable choice, evaluated through the proportion of vegetables, was the primary outcome, and the weight of vegetables and rice were the secondary outcomes. The mechanisms of the decision-making process were preliminarily explored through eye tracking.The usage of the nudging tableware significantly increased the proportion of vegetables and decreased the amount of rice taken (P<0.05), while insignificantly increased the weight of vegetables (P = 0.079). Eye tracking shows that the nudging plate significantly prolonged the food-choosing process and fixation duration on vegetables (P<0.05), and the latter was positively correlated to the increased quantity of vegetables while using the nudging plate (r = 0.493, P<0.01).The specially designed nudging tableware might be an effective and practical tool to promote the choice of less rice and more vegetables. Mechanisms behind this change might include automatic and unconscious processes with the inconspicuously smaller capacity of the bowl and larger portion size of the vegetable segment, and increased attention triggered by the vegetable patterns and larger green underpainting.