When people eat together in a workplace canteen, they tend to choose foods that are as healthy, or as unhealthy, as their colleagues, shows a US study published in April 2021 in the journal Nature Human Behavior.
Even people who are casual acquaintances have an influence.
This corroborates several observational studies showing the influence of social ties on weight gain, alcohol consumption and eating behaviors.
Douglas Levy, of Massachusetts General Hospital (MGH) and Harvard University, and his colleagues examined the social influence on the food choices of approximately 6,000 MGH employees, of different ages and socioeconomic status, who have eaten in the seven canteens of the hospital system for two years.
The wholesomeness of food purchased was determined using the hospital cafeteria labeling system, which designates all foods and beverages as green (healthy), yellow (less healthy), or red (unhealthy).
MGH employees can use their ID cards to pay in hospital canteens, which allowed researchers to collect data on individuals' food purchases, as well as when and where they purchased. these foods.
Participants' social networks were inferred by examining how many minutes apart two people shopped for food, how many times they ate at the same time over several weeks, and whether they went to different cafeterias at the same time. To validate their social network model, the researchers then surveyed more than 1,000 employees, asking them to confirm the names of people they had identified as their meal partners.
“The innovative aspect of our study was to combine complementary types of data and borrow the tools of social network analysis to examine how the eating behaviors of a large group were socially linked over a long period of time. Says Mark Pachucki, associate professor of sociology at the University of Massachusetts Amherst, co-author.
Based on three million encounters between pairs of employees making cafeteria purchases together, the analysis shows that purchases made by people related to each other were consistently more similar than different. The magnitude of the effect was somewhat stronger for healthy foods than for unhealthy foods.
A key part of the research was to determine whether social media actually influences eating behavior, or whether people with similar lifestyle and food preferences are more likely to become friends and eat together, a phenomenon known as homophilia. “We looked at what characteristics people had in common and analyzed the data from many angles. We have systematically found results which plead in favor of social influence rather than homophilia ”, specifies the researcher.
“If your eating habits influence the way your coworkers eat - if only a little - then changing your food choices for the better could benefit your coworkers too,” he says.