Some things that I have wondered about (all of which might lead to a lower lifespan in the US):
In many cases, depending upon where you are, Europe seems to have better public transportation. However, public transportation does not take you from exactly where you are to exactly where you are going. Instead it takes you from somewhere near where you are to somewhere near where you are going. You walk a bit at both ends. I have wondered whether a large number of short walks contributes to a longer life span.
Many years ago I was flying in to attend a meeting in Pittsburgh. Pittsburgh is the home of a large well known ketchup company. I happened to be sitting next to a ketchup expert, so we discussed ketchup. Who would have known that someone could be a ketchup expert? I asked him why ketchup in the US is so sweet. He said that there were federal regulations that require a lot of sugar in ketchup. Apparently this is considered a “health and safety” regulation. This got me to wondering what was the root cause behind the appearance that food in the US might not seem to be quite as healthy as food in Europe.
I am a pretty big guy (over 6 feet) and keep relatively active. I have noticed that in restaurants in the US the proportions are usually way greater than anything I could possibly eat in one sitting. I usually end up taking half my meal home. This does mean that I have a pretty good collection of plastic containers that originally came from restaurants (I use them for a range of other purposes). Why are our restaurant meals so large?
Of course all of these could contribute to greater obesity in the US.