In the same time period, we are working more hours than we used to (even though automation of everything was supposed to free up our time) and more and more of our jobs are sedentary.
I know as I get older and my career progresses, I am spending more and more time in a seat. And my job is more stressful, so I am at work more. Traffic is worse, so I can spend up to two and a half hours on the road a day (although it isn't usually that bad-more like an hour and a half). I have less energy to work out and less time to cook healthy. I can understand what is happening to people--especially people who don't have healthy habits before their lives get to the point of craziness where they have no personal time/energy.
And the work/life balance thing that companies sell us is bullshit. They don't care about anyone's life until they are so sick they can't come into the office.
In 12 years in IT I have worked one weekend (half a Saturday), and never more than 50 hours in a week. You gotta stand your ground.