Do you post photos of your meals or drinks on social media? If you do, you probably already know you're not alone. Besides hinting at which foods are popular — and giving the subset of people who complain about too much food clogging up their feeds something to complain about — those posts may help reveal something about our health. Scientists at the University of Utah decided to take a closer look.
Researchers surveyed nearly 80 million Twitter messages — a random sample of just 1% of publicly available, geotagged tweets — for one year. They then sorted through 4 million tweets about food for tweets that fell on opposite ends of the health spectrum: those that mentioned fast food restaurants, or lean meats, fruits, veggies or nuts.
They found that coffee was the most tweeted food or beverage in the continental United States between mid-2014 to mid-2015. Beer and pizza took second and third place, respectively. The fourth most popular food-related item was Starbucks, which fit into the fast food category. The seventh was chicken and was the only one out of the top 10 considered to be healthy food.
But the real insights came after cross-referencing the two types of food tweets with information about the neighborhoods they came from, including census data and health surveys. They found, for instance, that tweets from poor neighborhoods, and regions with large households, were less likely to mention healthy foods. Not surprisingly, people in areas dense with fast food restaurants tweeted more often about fast food.
Twitter has already been used to track health by gauging the prevalence of smoking and finding the source of outbreaks. The difference here is that these types of comparisons could provide clues as to how our surrounding neighborhood — the environment that we live, work and play in — affects our health and well-being.
"Our data could be telling us that certain neighborhoods have fewer resources to support healthy diets," says Quynh Nguyen, PhD, an assistant professor at the University of Utah College of Health. Nguyen is lead author of the study, published online today in JMIR Public Health and Surveillance. She explains that perhaps neighborhoods laden with fast food restaurants could benefit from having more supermarkets or farm stands that sell fresh produce.
There's evidence that tweets are more than just small talk. Areas with more chatter about walking, dancing, running and other physical activities had fewer deaths and lower rates of obesity. Positive sentiments toward healthy foods were also broadly related to fewer deaths and lower rates of chronic health conditions.
At this point it's too early to draw firm conclusions about what these findings could mean, says Nguyen. After all, tweets are biased. Twitter users represent a fraction of the population and skew toward 18 to 49 year olds. Plus, people are more likely to broadcast certain foods over others. You might be more inclined to tell your friends about a celebratory cupcake than a stack of celery sticks.
What's more, automated algorithms categorized tweets with about 85% accuracy. For example, initially computers labeled messages about basketball player Stephen Curry as food tweets. Future versions of the programs will integrate machine learning, which should improve results.
But the authors say the approach is too powerful to ignore. "This is a promising new, cost-effective method for studying the social and environmental influences on health," says senior author Ming Wen, PhD, professor of sociology at the University of Utah.
Top 10 tweeted foods
This work was supported by the National Institutes of Health's Big Data to Knowledge Initiative (BD2K).