ABC News January 10, 2014

The Fattest Jobs in America

WATCH: Is Your Job Making You Fat?

intro: Do you have a long commute in the car, only to get to work and sit at a desk all day? Do you work an overnight shift when the only dinner options are fast food?

Without proper exercise and healthy eating, your job could be helping you pack on the pounds.

According to results from a Gallup-Healthways Well-Being Index survey, which was released in May 2013, people who worked in transportation, manufacturing and repair industries were more likely to be obese. Obesity was defined as having a body mass index, or BMI, of over 30. Doctors were found to have the lowest level of obesity, with teachers, business owners and other professionals joining them at the bottom of the list.

In analyzing behavioral and emotional factors, the survey used data collected from January 2012 to September 2012 and was based on phone interviews with more than 139,000 American workers.

Separately, "Nightline" spoke to a few people in various lines of work about the struggles of staying healthy while on the job.

Troy Robbins is a 47-year-old trucker who drives up to 700 miles a day, spending up to 14 hours every day sitting. When he stopped to eat, his dining choices at truck stops ranged from greasy to greasier, and usually no salad in sight. He weighed almost 500 pounds before he started a fitness routine with "Rolling Strong."

Bob Perry, a fitness guru to long-haul truckers, developed the "Rolling Strong" program, which are fitness routines designed around the big rigs, from walking laps around the truck, to doing "stairs" on the truck steps, to doing exercises inside the rig.

Below is the list of 14 professions, according to Gallup's findings, ranked in order of which had the greatest level of obesity.

quicklist: 1 title: Transportation text: 36.4 percent

quicklist: 2 title: Manufacturing or production text: 29.9 percent

quicklist: 3 title: Installation or repair work text: 28.3 percent

quicklist: 4 title: Clerical or office work text: 26.6 percent

quicklist: 5 title: Manager, executive or official text: 25.6 percent

quicklist: 6 title: Service worker text: 25.6 percent

quicklist: 7 title: Nurse text: 25.2 percent

quicklist: 8 title: Fishing, farming or forestry text: 24.7 percent

quicklist: 9 title: Construction or mining text: 24.0 percent

quicklist: 10 title: Sales text: 23.2 percent

quicklist: 11 title: Professional (excluding physicians, nurses and teachers) text: 22.1 percent

quicklist: 12 title: Teacher (K-12) text: 20.9 percent

quicklist: 13 title: Business owner text: 20.4 percent

quicklist: 14 title: Physician text: 14.0 percent