The actual traditional Japanese food consists of obscene amount of carbohydrates taken with pickles flavored salt with little to no protein or fat intakes. The role of carbs and proteins is switched from a stereotypical European dinner, a meal is about how to deal with the grains. This naturally shortens body heights and take diabetics out of family lines. This had changed massively owing to Westernization of diet and had reduced stroke(brain and heart) deaths even as recent as last ~30 years.
This is apparently weird even to Chinese people; an image of ramen with rice and roast dumplings on sides amounts to a ragebait to them(as well as to experts in cardiovascular systems), while it's nothing more than a common lunch menu to students and young workers in Japan.
But I digress - my point is, the real traditional Japanese meal is more like half a football worth of rice with vegetable flavored salt, quite unlike idealized modern interpretations thereof.
Otherwise correct, but the real real traditional Japanese diet was barley (mugi), millet (kibi/hie) and sorghum (awa), not just white rice, which was an unaffordable luxury for many peasants.
The article also mentions that 60 years ago, Japan had the lowest proportion of 100+ year olds.
Gemini disagrees with this.
Try an actual source: https://2024.sci-hub.se/1147/ff0abbc773b295a97bc927b98dcaed9...
It is true that rice was always the prestige food consumed by the upper classes, and the peasantry ate rice too, but it was only one of the five staples (gokoku) and was often extended with other grains (mugigohan etc).
Mugi/awa/hie were untracked substitutes for rice. Medieval Japanese warlords mainly collected taxes in form of bags of rice, and ignored other crops. So peasants mixed those grains into rice at varying ratios of up to 100% depending on local and yearly yields. That doesn't mean those grains were culturally considered defaults.
Your pdf is mostly about the 1870s and later. (Although it does mention the Tokugawa period, which began in 1603, it seems to do so for quite tangential reason.)
In contrast, people in East Asia started cultivating rice 9,000 years ago, and modern Japanese are probably mostly descended from these early rice farmers (who started out in China, then spread to Korea and then Japan) with a substantial contribution from another population called Jomon, which were already in Japan when the heavily-rice-dependent people started to arrive in Japan about 2,300 years ago and who lived mostly by hunting and gathering.
This is relevant because some people here are advocating for everyone to adopt a Japanese-like diet, which might not turn out so well for you unless most your ancestors have 8,000 or 9,000 years of experience getting most of their calories from grains.
We're not really disagreeing here? But wet paddy rice farming requires flat land, which in mountainous Japan is in notably short supply, so they planted other crops too.
This parallels China, where the warm, wet south is rice country but the colder, drier north grows other grains. The five grains (gokoku) idea is itself originally Chinese:
https://en.wikipedia.org/wiki/Five_Grains
Gemini thinks there are two "g"s in "guava" as of two weeks ago when I tested it.