黄帝曰。愿闻人之不食七日而死何也。伯高曰。臣请言其故。胃大一尺五寸。径五寸。长二尺
六寸。横屈受水谷三斗五升。其中之谷。常留二斗。水一斗五升而满。上焦泄气。出其精微。 悍
滑疾。下焦下溉诸肠。小肠大二寸半。径八分分之少半。长三丈二尺。受谷二斗四升。水六升三合合
之大半。回肠大四寸。径一寸寸之少半。长二丈一尺。受谷一斗。水七升半。广肠大八寸。径二寸
寸之大半。长二尺八寸。受谷九升三合。八分合之一。肠胃之长。凡五丈八尺四寸。受水谷九斗二升一
合合之大半。此肠胃所受水谷之数也。平人则不然。胃满则肠虚。肠满则胃虚。更虚更满。故气得
上下。五脏安定。血脉和。则精神乃居。故神者。水谷之精气也。故肠胃之中。常留谷二斗。水一斗
五升。故平人日再后。后二升半。一日中五升。七日五七三斗五升。而留水谷尽矣。故平人不食饮
七日而死者。水谷精气津液皆尽故也。
此论人之脏腑形骸。精神气血。皆藉水谷之所资生。水谷绝。则形与气俱绝矣。六节藏象论曰。
五味入口。藏于肠胃。味有所藏。以养五气。气和而生。津液相成。神乃自生。故神者。水谷之精
气也。平人不然者。谓平常无病之人。胃满则肠虚。肠满则胃虚。日夜消化。只留三斗五升。无有
如此之留积也。是以不饮食七日。则所留
之水谷尽矣。水谷尽。则精气津液皆尽矣。王芳侯曰。病患不饮食七日不死者。水谷留积故也。盖留
积则为病矣。
黄帝说：我想了解一下，人为什么在七天不进食后会死亡呢？
伯高回答说：请允许我说明其中的原因。人的胃容量大为一尺五寸，直径五寸，长二尺六寸，弯曲部分能容纳水谷三斗五升。其中谷物通常留存二斗，水一斗五升，此时胃便满了。上焦宣发气机，排出精微物质；卫气（悍滑疾之气）运行迅速，向下焦灌注滋养各个肠道。小肠直径二寸半又八分之一分，长三丈二尺，能容纳谷物二斗四升，水六升又大半合。回肠直径四寸又三分之一寸，长二丈一尺，能容纳谷物一斗，水七升半。广肠直径八寸又三分之二寸，长二尺八寸，能容纳谷物九升又三分之一合。肠胃的总长度，共计五丈八尺四寸，总共能容纳水谷九斗二升又大半合。这就是肠胃所能容纳的水谷的数量。
正常健康的人则不是这样。胃充满时，肠道就是空虚的；肠道充满时，胃就是空虚的。胃肠虚实交替变化，因此气机能上下通达，五脏安和，血脉调和，精神才能安居体内。所以，神气是水谷化生的精气。因此，肠胃之中常留存的谷物为二斗，水为一斗五升。所以正常人每天排便两次，每次排出二升半，一天共排出五升。七天下来，五七得三十五，即三斗五升，此时原本留存的水谷就排尽了。所以，正常人如果不饮食七天而死亡，是因为水谷、精气、津液都耗尽的缘故。
这段论述了人的脏腑形骸、精神气血，都是依靠水谷来滋养生成的。如果水谷断绝，那么形体与气机都会随之衰竭。《素问·六节藏象论》说：“五味入口，藏于肠胃，味有所藏，以养五气，气和而生，津液相成，神乃自生。”所以说，神气是水谷的精气。文中所说的“平人不然”，是指平常没有疾病的人，胃满时肠虚，肠满时胃虚，日夜进行消化，只留存三斗五升的水谷，并没有如此多的积滞。因此，如果不饮食七天，那么所留存的水谷就排尽了。水谷排尽，精气津液也就都耗尽了。王芳侯说：病人七天不进食却没有死亡的，是因为体内仍有水谷积滞的缘故。大概因为积滞存在，这就属于病态了。
Huangdi said: I wish to hear why a person dies after seven days of not eating.
Bo Gao replied: Please allow me to explain the reason. The stomach has a capacity of one chi and five cun in circumference, a diameter of five cun, and a length of two chi and six cun. Its curved portion can hold three dou and five sheng of food and water. Typically, it retains two dou of grain and one dou and five sheng of water, at which point it is full. The Upper Jiao (Upper Burner) disperses Qi, releasing fine essences. The vigorous, swift-moving Wei Qi (Defensive Qi) flows downward to irrigate the various intestines. The small intestine has a diameter of two cun and half, plus one-eighth of a fen, and a length of three zhang and two chi. It can hold two dou and four sheng of grain and six sheng and more than half a he of water. The returning intestine (Hui Chang) has a diameter of four cun plus one-third of a cun, and a length of two zhang and one chi. It can hold one dou of grain and seven sheng and a half of water. The broad intestine (Guang Chang) has a diameter of eight cun plus two-thirds of a cun, and a length of two chi and eight cun. It can hold nine sheng and one-third of a he of grain. The total length of the gastrointestinal tract is five zhang, eight chi, and four cun, capable of holding a total of nine dou, two sheng, and more than half a he of food and water. This is the quantity of food and water that the gastrointestinal tract can contain.
However, a healthy person is different. When the stomach is full, the intestines are empty; when the intestines are full, the stomach is empty. Through this alternating cycle of fullness and emptiness, Qi circulates up and down, the Five Zang Organs remain stable, and the blood vessels are harmonious, allowing Shen (Spirit) to reside within. Therefore, Shen is the refined essence derived from food and water. Consequently, the gastrointestinal tract typically retains two dou of grain and one dou and five sheng of water. Thus, a healthy person defecates twice daily, expelling two sheng and a half each time, totaling five sheng per day. Over seven days, 5 x 7 equals 35, or three dou and five sheng, meaning all retained food and water are exhausted. Therefore, if a healthy person dies after seven days without eating or drinking, it is because the food, water, refined essence, and Jin-Ye (Body Fluids) have all been depleted.
This passage discusses how the human viscera, physical form, Shen, Qi, and Blood all rely on food and water for nourishment and generation. If food and water are cut off, both form and Qi will perish. The *Ling Shu · Chapter 6: Six Sections and Visceral Manifestations* states: "When the five flavors enter the mouth, they are stored in the gastrointestinal tract. The flavors are stored to nourish the Five Qi. When Qi is harmonious, life arises; when fluids and liquids are formed together, Shen naturally generates." Hence, Shen is the refined essence of food and water. The phrase "a healthy person is different" refers to ordinary individuals without disease, whose stomachs are full while their intestines are empty, and vice versa. They digest continuously throughout the day and night, retaining only three dou and five sheng, without such accumulation. Therefore, after seven days without eating, the retained food and water are completely expelled. Once the food and water are gone, the refined essence and body fluids are also depleted. Wang Fanghou stated: Patients who do not eat for seven days but do not die do so because of retained food and water accumulation. Generally, retention constitutes a pathological state.