(also spelled , and sometimes misspelled ) is a

Confucian Confucianism, also known as Ruism or Ru classicism, is a system of thought and behavior originating in ancient China. Variously described as tradition, a philosophy, a Religious Confucianism, religion, a humanistic or rationalistic religion, ...

teaching that instructs people to eat until they are 80 percent full. The

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

ese phrase translates to, "Eat until you are eight parts (out of ten) full", or "belly 80 percent full".

Okinawans

As of the early 21st century,

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

ns in

continue practicing . They consume about 1,800 to 1,900 kilo-calories per day. Their elders' typical

body mass index Body mass index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and he ...

(BMI) is about 18 to 22, compared to a typical BMI of 26 or 27 for adults over 60 in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. Okinawa has the world's highest proportion of

centenarian A centenarian is a person who has reached the age of 100 years. Because life expectancies worldwide are below 100 years, the term is invariably associated with longevity. In 2012, the United Nations estimated that there were 316,600 living cente ...

s, at approximately 50 per 100,000 people. Biochemist

Clive McCay Clive Maine McCay (21 March 1898 – 8 June 1967) was an American biochemist, nutritionist and gerontologist. Biography McCay was professor of animal husbandry at Cornell University from 1927 to 1963. His main interest was the influence of n ...

, a professor at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...

in the 1930s, reported that significant

calorie restriction Calorie restriction (caloric restriction or energy restriction) is a dietary regimen that reduces intake of energy from caloric foods & beverages without incurring malnutrition. "Reduce" can be defined relative to the subject's previous intake be ...

prolonged life in laboratory animals. Authors Bradley and Craig Wilcox and Makoto Suzuki believe that may act as a form of calorie restriction, thus extending practitioners'

life expectancy Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...

. They believe assists in keeping the average Okinawan's BMI low, and this is thought to be due to the delay in the stomach stretch receptors that help signal

satiety Satiety ( ) is a state or condition of fullness gratified beyond the point of satisfaction, the opposite of hunger. It is a state which induces meal termination.Hetherington, M.Sensory-specific satiety and its importance in meal termination ''Neuro ...

. The result of not practising is a constant stretching of the stomach which in turn increases the amount of food needed to feel full.

In other cultures

The approach to eating of is also found in other cultures.

China

The teaching is

, a belief system dating back to the 5th century BCE China. A similar saying to the Confucian one is found in

Traditional Chinese Medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action ...

: (, "only eat until you are 70 percent full.")

India

The principle also appears in

Ayurvedic Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population rep ...

medicine, dating back to the 4th century BCE, where "you should fill one third of the stomach with liquid, another third with food, and leave the rest empty."

Influence

Zen

In the 1965 book '' Three Pillars of Zen'', the author quotes

Hakuun Yasutani was a Sōtō rōshi, the founder of the Sanbo Kyodan organization of Japanese Zen. Biography Ryōkō Yasutani (安谷量衡) was born in Japan in Shizuoka Prefecture. His family was very poor, and therefore he was adopted by another family. ...

in his lecture for beginners as telling his students about the book (''Precautions to Observe in'' ), written circa 1300, which advises practitioners to eat about two-thirds of their capacity. Yasutani advises his students to eat only eighty percent of their capacity, and he repeats a Japanese proverb: "eight parts of a full stomach sustain the man; the other two sustain the doctor".

American culture

was popularized in the United States by a variety of modern books on diet and longevity.

References

Footnotes

{{Japanese social terms Eating behaviors of humans Diets Gerontology Japanese proverbs