"To eat until fully sated invites misfortune later." That is one line from the *Yojokun*, written in 1713 by Kaibara Ekken. The book runs to eight volumes and treats daily meals, exercise, and even the state of one's mind as things to be tended, both body and heart. The idea that "resting is a form of weakness" still lingers in workplaces today. But 300 years ago in Japan, a book already existed that laid out, at this length, how to rest and how to tend the body. That fact alone counts as a kind of rebuttal.

He finished all eight volumes the year before he died

Kaibara Ekken (1630–1714) was born the fourth son of Kaibara Kansai, a scribe serving the Fukuoka domain (now Fukuoka Prefecture). Sent to study in Kyoto under orders from the domain, he studied Neo-Confucianism and honzogaku (the study of medicinal natural history). A record held by the Nagoya University School of Medicine Library recounts this background and describes the *Yojokun* as "a book of practical teaching, written plainly and concretely, on what one should keep in mind in daily life to preserve health of body and mind and to live long, drawing on Japanese and Chinese precedents and on the author's own experience." It was completed in 1713, the year before Ekken died.

The contents are divided, in the Nakamura Gakuen University archive, into eight volumes running from Volume One through Volume Eight. Meanwhile, the record for the 1713 (Shotoku 3) edition held by the Nagoya University School of Medicine Library lists the title as "Yojokun, 4 volumes" and its format as "4 bound books." Even the same text, in other words, gets counted differently depending on who is counting. It was published by the Kyoto printing house Nagata Chobei. A search for "Yojokun" on the National Diet Library Search turns up numerous modern editions alone, including the Kadokawa Sophia Bunko *Kogoyaku Yojokun* and the Chuko Bunko revised edition of *Yojokun*. The results suggest that a book written 300 years ago is still being read today, in edition after edition.

Eat until eighty percent full, then walk a little afterward — it was already written down

From among its many lines, here are three that map directly onto how we eat and spend our evenings today.

On meals, Ekken writes: "Even facing a fine and beautiful meal, one should stop at eight or nine parts out of ten. To eat until fully sated invites misfortune later." Stop at eighty or ninety percent, even with a feast in front of you — eating to full satiety, he warns, brings trouble afterward. The phrase "eighty percent full" itself came into common use later, but the underlying caution — stop at eight or nine parts out of ten — was already written down 300 years ago.

There is guidance on what to do after eating, too: "After a meal in particular, one should always walk several hundred steps." Don't stay seated — walk a little, the line says. On the mind, it continues: "Do not let anger, sorrow, grief, or worry run to excess. Keep the mind level and the spirit calm." Don't let anger, sadness, or rumination run out of control. Keep the mind level — that is the teaching.

An attitude that existed long before the word for "tending" oneself did

These lines overlap in places with health information circulating today. Japan's Ministry of Health, Labour and Welfare's e-Health Net reports that how much a person moves during the day relates to how long and how deeply they sleep, and that people with an exercise habit reportedly fall asleep more easily and wake less often during the night. The 300-year-old line "after a meal in particular, one should always walk several hundred steps" and this modern reporting point in the same direction: both recommend moving the body.

One caveat belongs here. The *Yojokun* is not a medical text — it is a book of practical teaching grounded in experience and Confucian ethics, not something to be read as a guarantee of medical effect. Even so, a fact worth holding onto remains: 300 years ago in Japan, a book that treated body and mind as things to be tended daily was published by a printing house in Kyoto. Resting and tending oneself are not recently invented attitudes. My own reading is this: the fact that a 300-year-old book of teachings is being read anew may reflect a kind of full circle — a return to the plain fact that "just keep pushing through" was never enough to sustain body or mind. That a book called "Kyuyogaku" (the science of rest), sitting on bookstore shelves today, has reportedly sold 160,000 copies looks like further evidence that this attitude is still needed now.

Set tonight's plate down at eighty percent. Walk a few hundred steps before the dishes

  1. Tonight, try putting your chopsticks down around eighty percent through the meal on your plate. Ending on "I could eat a little more" is about right.
  2. After the meal, before the dishes, try walking a few hundred steps around the house. It doesn't need to be real exercise.
  3. Before bed, try writing down one thing that made you angry or worried that day, and practice setting it down there, just once.

If you manage a health condition that requires controlling your diet, please don't rely on your own judgment of "eighty percent full" as a guideline — talk to your doctor instead.

"To eat until fully sated invites misfortune later." A line written 300 years ago still fits, as it is, onto tonight's table.

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