If you are working a minimum wage job, you have a higher chance of becoming obese. Why? Because you are constantly worrying about paying off your bills that you have little time to take care of your body and get healthy.
Also, when your refrigerator is not stocked with food, you are more likely to overeat every chance you get because you have no idea when the next full meal will come. Having full access to food allows you to take care of more important things than worrying about going hungry.
Countries with high levels of job and income security have much lower overweight population.