>The most obvious answer is the proliferation of food that is extremely calorically dense and designed to promote fast and heavy consumption.
Or you could wave your hands and say "People these days are just irresponsible!"
Could it not be both? Food may have gotten more unhealthy, but people have also grown more complacent with what and how much they put into their bodies. You can't expect everyone else to coach you on how to eat healthy, you must do it yourself.
Sure! It definitely could be. I'd be interested to see if there has been some documented cultural shift, independent of marketing by food giants. One generation seems like a short time frame for that kind of thing though.
But for now, the most direct and clear link is between the food available and people's weight.
