Adjusting font sizes for calorie numbers on food menus could 'nudge' customers to make healthier food choices. The corresponding study was published in the International Journal of Hospitality Management.
Research shows that Americans spend at least 50% of their food budget on eating out. To help encourage healthy eating, the US Food and Drug Administration (FDA) mandated the Menu Labeling Final Rule, which requires restaurants with 20 or more locations to post nutritional information on their menus. Understanding how such information could be displayed to nudge healthy eating behaviors could help restaurants serve healthier foods to their customers while still turning a profit.
For the current study, researchers randomly assigned participants into one of two groups. In the first group, participants were given menus in which calorie numbers were proportional to font sizes ie. calorie numbers and font sizes increased together. In the second group, the inverse occurred; as calorie numbers increased, font size decreased. The researchers also assessed how 'health-conscious' participants were and asked some to make decisions within varying time limits to determine how time constraints affected decision-making.
Ultimately, the researchers found that participants in the second group- in which font sizes and calorie numbers were incongruent- were more likely to choose healthier food options than those in the first group. This pattern was most prominent among those who were less health conscious- especially when they had limited time to choose.
The researchers noted that their study is an example of the 'Stroop Effect' ie. when incongruity delays decision-making- in this case, when smaller numbers are in a larger font and vice versa. Another example of this principle is reading the color 'purple' written in green font. Studies show that it takes respondents longer to call out the color they're seeing when it is incongruent with the written word. Researchers thus use his principle to assess attention capacity and processing speed.
"Healthy food items could be profitable for restaurants, but whenever a 'healthy' label is attached, people may assume it does not taste good," said lead study author, Dr. Ruiying Cai, an assistant professor in the Washington State University's School of Hospitality Business Management, in a press release, "We're trying to provide restaurants with subtle cues, rather than saying it out loud."