Social media reveals link between geography and diet

The more difficult it is to access groceries, the less healthy your diet is likely to be — or at least the diet that you’re telling the world about. That’s the result of a social media analysis that compared the food choices of those living in so-called food deserts — communities with limited access to grocery stores — with those who have easy access to purchase food.

The study, by researchers from Georgia Institute of Technology, found people in food deserts eat food that is 5–17% higher in fats, sugars and cholesterol.

For example, in the north-eastern states of the US, plates would be filled with pork, mayonnaise and cookies in more isolated regions, versus bagels, kale and hummus elsewhere.

The study analysed three million geo-tagged Instagram posts to identify the food choices and nutritional profiles of people living in both types of communities throughout America.

Munmun De Choudhury, an assistant professor in Georgia Tech’s School of Interactive Computing, led the study.

“Instagram literally gives us a picture of what people are actually eating in these communities, allowing us to study them in a new way.”

The study also identified the ‘signature’ foods of four additional US regions, comparing the results in food deserts and non-food deserts.

The biggest difference the researchers found was in fruits and vegetables, with 48% of posts from people in non-food deserts mentioning them, versus only 33% in food deserts.”

The research team used the United States Department of Agriculture’s (USDA) database of nutritional values for nearly 9000 foods to create a nutritional profile for both groups. The number of kilojoules didn’t differ significantly, but the levels of fats, cholesterol and sugars were much higher in food deserts, especially in the West and Southwest.

An interesting side note from the study is that pictures of meals that are most likely to be posted by both groups tend to be the staples of each region: steak and coffee in the West; lox and cheesecake in the East; okra and biscuits in the South.

“It doesn’t matter where you live,” De Choudhury said. “Everyone seems to eat what their region is known for.”

The study, ‘Characterizing Dietary Choices, Nutrition, and Language in Food Deserts via Social Media’, was presented at the ACM Conference on Computer-Supported Cooperative Work and Social Computing on 27 February–2 March 2016 in San Francisco.