Your Commute May Be Making You Fat, Study Suggests

Driving by a fast-food joint on your way home from work may be driving your weight problem, a new study suggests.

The study, published Wednesday in the journal PLOS One, analyzed the link between body mass index – a measure of obesity that takes into account height and weight – and the availability of supermarkets, grocery stores, restaurants and fast-food places near about 700 people’s neighborhoods and workplaces, as well as along routes between the two.

On those commuter routes, the availability of fast food was closely linked to higher body mass index: In fact, each additional fast-food restaurant located within a kilometer, or about 0.62 miles, of a commuting route contributed to increased BMI, the study found.

“The fast-food options are too many and very convenient, which results in higher BMI when compared to routes with fewer fast-food retailers,” says study author Adriana Dornelles, a statistician and clinical assistant professor of economics at Arizona State University.

The analysis encompassed 710 female elementary school employees who lived in the Orleans, Jeffersonor St. Charles parishes in the greater New Orleans area in 2008. About 73% of those included in the study were white, and nearly two-thirds were 40 to 59 years old. Their median household income was $38,852, and on average, they commuted 25.2 minutes each day.

Nearly 42% of those studied were obese, while another 29.3% were overweight and just 15.1% got more than 30 minutes of physical exercise per day.

Dornelles designed likely commuting routes between people’s homes and workplaces to conduct the analysis, based on the shortest distance they’d have to travel. The study notes that “incentives of price and time are particularly salient for full-time workers who often work long hours and do not have time to cook at home.”

When analyzing residential, worksite and commute food environments together, more fast-food restaurants, supermarkets and grocery stores – smaller retailers that may lack fresh produce or healthy options – near a person’s home also were significantly linked to an increase in BMI.

The availability of full-service restaurants in residential areas, meanwhile, was tied to a significant decrease in BMI.

“Neighborhoods with more full-service restaurants promote healthier environments than those with a predominance of fast-food retailers,” Dornelles says. “In general, people who choose to dine in are more aware of their diets … than those who opt for quick-easy-cheap choices.”

The link between BMI and neighborhood supermarket availability surprised Dornelles. She had theorized that a greater number of supermarkets would be associated with lower BMI because they may be stocked with healthier options.

“We do not know what exactly customers buy when they stop at supermarkets,” Dornelles says. “What we know is that the presence of supermarkets offers a better alternative for healthy eating than grocery stores and convenience stores.”

Around the workplace, meanwhile, the number of full-service restaurants and grocery stores had a “decreased but significant” effect on BMI. That’s potentially because school employees tend to have limited time to eat and may choose to stay at school for lunch, the study says.

Future research should focus on a “participant’s exact commute routes, what types of food stores they visit, and what types of food they buy in their home-to-work and work-to-home commutes,” the study says.

“Interventions that (target) reducing fast-food meal frequency and accessibility of fast-food restaurants should be considered,” Dornelles wrote.