Funny that you say it, but I think Japan doesn't eat any healthier than the average European country. Coming from the USA, I can see how the conclusion might change.

I come from a country that isn't well-known for its cuisine but live quite long lives, but I still gained (and lost when I left) about 7kg when I lived there.

Nothing about their high-sugar, high-sodium, no-fruits diet seemed particularly healthy.

Okinawans eat very differently than people who live in Tokyo, I guess.