I think lifestyle has definitely got something to do with it.
Change in technology. Eg, 30yrs ago, I don't recall whipper snippers being around, things were down by hand (garden shears). No blower vacs - manual sweeping. These 2 inventions have reduced the overall effort to burn of calories. Another eg, are TV games, in my days you went out the yard and kicked a ball around. Some kids favour playstation over backyard cricket.
Fear - 30yrs ago as a 10yr old I'd be walking to school 300m+ up the rd, these days with weirdos around, parents prefer to drop kids off in cars - exercise is lost.
Workforce - there is a decline in blue collar, hard labouring jobs these days. Automation has taken care of a lot manual work. Eg, garbos no longer need to lift bins into the trucks, its done automatically.
There is a shift from blue collar to white collar occupations. People sitting on their butts 8-10hrs a day, punching keyboards - not really a calorie burner!
Many blue collar processing jobs have gone offshore as well.
Available of food choices. 30-40yrs ago Hungry Jacks, Maccas, KFC were around, but not in every town. 2ndly these were treats once in a very blue moon. Now, some people have these as regularly lunch meals once, twice a week.
Even foods/beverages - coke, cholocates - they have been around for yonks, but again, these were treats, now these are consumed without much thought.
I know there is more, but the above is just an example. Thats my 2bw!
