I wouldn’t be surprised if keeping moving contributed more to not dying than diet specifics.

My understanding (albeit only gathered from blogs/YouTube videos/Google Maps) is that the biggest difference is parking. On-street parking is mostly not allowed, free parking at businesses is mostly limited to car-centric ones like mechanics and dealerships, and you can't register a car without proving that you have a place to park it. Tens of millions of Japanese people living in less-dense areas have no problem with that, but in Tokyo it's prohibitively expensive for the average person due to land cost. This means that even in suburban areas, roads are narrower and everything is closer together.

I think this can be seen in cities with walking-to-work culture (often metro/underground).

Although I've wondered if cause is enforced exercise or just selection (people that move to a large city to work have a demographic).