BOSTON, Mass. — In many offices, friendly co-workers often time their meal breaks so they can eat and talk together. A new study finds these friends aren’t just dining together, they’re likely picking the same foods too. Researchers from Massachusetts General Hospital say what someone has for lunch isn’t always what they’re craving the most — it’s what they see on their colleague’s tray instead.
“We found that individuals tend to mirror the food choices of others in their social circles, which may explain one way obesity spreads through social networks,” says Douglas Levy, PhD, in a media release.
Researchers examined the eating habits of around 6,000 MGH employees over two years. The workers all come from diverse backgrounds, socioeconomic statuses, and age groups, but have one thing in common — they take their meal breaks in one of the hospital system’s seven cafeterias. Researchers say co-workers don’t just tempt friends to eat unhealthy foods, this influence can actually extend to healthy choices too.
Meal choices are all about who you’re around?
Study authors say they had an easy time of knowing what people ate thanks for the hospital’s food labeling system. All food and beverages get a label of green (healthy), yellow (less healthy), or red (unhealthy). The study was also able to monitor when and who made these purchases because the hospital staff can pay for meals using their ID cards. With this data, researchers could make assumptions about each employee’s social networks.
“Two people who make purchases within two minutes of each other, for example, are more likely to know each other than those who make purchases 30 minutes apart,” Levy explains.
However, to validate their hunches, the team also surveyed over 1,000 MGH employees about their social circles at work. Each person confirmed or corrected the names of the people study authors suspected to be their dining partners.
“A novel aspect of our study was to combine complementary types of data and to borrow tools from social network analysis to examine how the eating behaviors of a large group of employees were socially connected over a long period of time,” says co-author Mark Pachucki, PhD, associate professor of Sociology at the University of Massachusetts, Amherst.
In total, researchers gathered information on three million lunchtime encounters between groups of employees making meal choices together. Results reveal these food purchases consistently look more alike than they do different. Surprisingly, the study finds the influence to eat healthy foods actually appears stronger than it does for unhealthy foods.
Is this social pressure or human nature?
Levy’s team also wanted to determine if this trend is more about social networks influencing an eater’s decisions or a phenomenon called homophily. This is the tendency of people with similar lifestyles and food preferences to become friends and eat together more often.
“We controlled for characteristics that people had in common and analyzed the data from numerous perspectives, consistently finding results that supported social influence rather than homophily explanations,” Levy reports.
So why do social circles all seem to eat the same foods? Study authors believe the answer could be as simple as peer pressure.
“People may change their behavior to cement the relationship with someone in their social circle,” Levy says.
The associate professor of Medicine at Harvard Medical School adds co-workers can also give each other the support someone feels they need to make an unhealthy choice. At the same time, they can also push a colleague into passing on the burger and going for the salad.
Could this be a good thing for curbing obesity?
Study authors note the findings may have bigger implications for public health strategies targeting obesity in the workplace. One option could be to start looking at pairs of people instead of individual dieters. Company lunch rooms could offer two-for-one sales on healthy foods like salad but no discounts for unhealthy snacks.
“As we emerge from the pandemic and transition back to in-person work, we have an opportunity to eat together in a more healthful way than we did before,” Pachucki concludes. “If your eating habits shape how your co-workers eat—even just a little—then changing your food choices for the better might benefit your co-workers as well.”
The study appears in the journal Nature Human Behaviour.