If you’re trying to lose weight, think about that drive to work.

A study of hundreds of US primary school workers has found those whose daily commute passes through a corridor with more fast food restaurants have a higher body mass index (BMI), the measure used to gauge overweight and obesity.

It’s the first ever study to link body weight and the availability of fast food on the journey to work.

The study’s author, biostatistician Adriana Dornelles, from the Department of Economics at Arizona State University, US, brought together three large databases to make her findings.

She took figures from the ACTION survey, including the age, weight and education level of 710 elementary school employees – 73% of whom were teachers – across 22 schools in Greater New Orleans.

Dornelles then used the Dun and Bradstreet commercial database to create maps of the food outlets located within one kilometre of each person’s home, the school they worked in, and their presumed commuting route while driving.

Food outlets were classed as supermarkets, grocery stores, full-service restaurants and fast food restaurants, and the commute route was based on the shortest distance between home and work, which studies suggest is how most people navigate the trip.

Finally, US Census data were tapped to measure income, used as a proxy for socioeconomic status.

The results show that for people trying to keep weight off, choosing which way they go to work is no small matter.