Previous research suggests there may be a social component to obesity. Some studies have shown that people who have a lot of overweight or obese friends are more likely to be heavy themselves.
Now a new study suggests that who you email may reveal your weight status.
A study of workplace emails found a strong link between the frequency coworkers emailed each other and body mass index (BMI), a measure used to determine obesity. The analysis of emails found obese co-workers were more likely to email each other.
Study co-author Dr. Elizabeth Rula, executive director and principal investigator at the Healthways Center for Health Research, told CBSNews.com her team was surprised to find this link in a random assortment of emails. She hopes these social networks at the workplace can be used to spread more healthful messages.
"These findings meaningfully advance our approach to total population health management," she said.
The study, published in a February issue of PLoS One, involved employees working at several U.S. offices of Healthways who had been screened for their BMIs, a ratio of height over weight. People with a BMI of 18.5 to 24.9 are considered normal weight, those with a BMI 25 to 29.9 are overweight and those with a BMI of 30 or greater are considered obese, according to the National Institutes of Health.
After reviewing more than 5 million emails from more than 2,000 employees, the researchers mapped a corporate social network that showed which employees were most influential to their peers and which employees were more likely to pick up certain health traits, in this case being thin or overweight.
"No previous research has demonstrated that health traits correlate across social ties in a network of coworkers, especially using ties identified through readily available data such as email traffic," Dr. Luke Matthews, director of analytics at the firm, Activate Networks, said in a statement.
Since most companies have access to employees' emails, Rula thinks targeting a particular person in a social network with lots of influence may be an ideal way to promote a healthy campaigns in the workplace.
from Healthways and Gallup also reported a link between social relationships and obesity after finding clusters of obesity rates in certain areas of states.
Study author Dr. Carter Coberley, vice president of health research and outcomes at HealthWays, told CBSNews.com at the time, he didn't "want to go so far as to say your friends are making you fat," but perhaps there were certain obesity drivers in these regions that researchers could look at.
Besides obesity, previous research has showed social networks could play a role in our health, including affecting smoking behaviors, happiness and levels of exercise and other activity.
Dr. Nicholas Christakis, a social scientist at Harvard Medical School, is a pioneer in this field of social networking and health, and has worked on many of those studies. He said the newest research adds more evidence to the power of social contagion.
"Social influence in the workplace profoundly affects many aspects of our lives, including our health," Christakis said in a statement. "This study contributes importantly to our understanding of the power of social networks at work, and it does so by tracing the email communications among people."