Looking beyond eating habits, a main factor that leads to obesity today is the American workplace. Most people think its all about the food, but the work environment has changed drastically and therefore more jobs require less physical activity which explains the steady weight gain. In the Industrial vs. Modern world we can see that jobs 50 years ago included farming, factories, miners, and spinners whereas today, jobs include phone operators, transportors, office, teachers, and bankers.
https://www.nytimes.com/2011/05/26/health/nutrition/26fat.html
https://conscienhealth.org/2015/12/food-policy-obesity-policy/
Reduction of activity levels in workplace from 1960-2010 is clearly portrayed in this statistical visual aid, we can see that there are more jobs in the U.S that require light to sedentary lifestyles. This means that machines/technology takes over the physical activity that usually one wouldve done in the 1960’s – 1980. There is a decrease on moderate lifestyle because as stated before, less jobs now require less physical acitvity. 
https://www.lifespanfitness.com/workplace/resources/articles/health-risks-of-a-sedentary-lifestyle
