The article points to by-products of industrialization (namely industrial chemicals and artificial lighting) as potential culprits in the case of rising obesity, but the distribution of obesity doesn't match level of industrialization across countries. Obesity is seemingly focused in North America plus other anglophone countries, while mostly absent in other highly industrialized countries like Japan and Norway. Red herring, perhaps?
Hmm, well one thing I've noticed is that people in Tokyo walk/bicycle a lot more than most people in any American city I've lived in. Not intentionally, really, but simply as a side-effect of the non-car-oriented transportation system and urban design that results in highly walkable environments. Anecdotally, co-workers who had temporary assignments to other locations where they drove everywhere complained of gaining 5-10kg over the year or so they were there.
I regularly see things in Japan like dressed-up women in high-heels, elderly people, and other non-particularly-athletic-looking types, sprinting up long staircases to make the train. In the U.S. I would be quite surprised to see anyone sprinting in public...
Portions also often seem to be smaller. While of course it's easy enough to order large portions in Japan ("oomori kudasai!"), there's far less of the feeling of hard-to-avoid excessively large portions I often seem to get in the U.S. In Japan, "small" always seems to be on the menu, and is often the default; in the U.S., not so much...
I think it's important that such things are not unusual and "intentional" actions that you have to remember to do (and can easily shirk), but rather are a side-effect of the environment, and so happen all the time, even when you're tired, even when you're busy, even when you're out with friends to play, etc.
