The Secret of Secrets and Other Philosophical Treatises

...to cease while the will—that is, the desire for eating—still remains. By eating too hastily, first the stomach is constricted, the body is burdened, and the spirit is harmed. What remains of the food in the depths of the stomach is heavy and harmful original: "nonus," likely a scribal error for "nocivus", from which diseases arise.

Regarding the drinking of water

Similarly, refrain entirely from drinking water with your food, and do not let it become a habit for you. For drinking cold water during a meal cools the stomach and, if much is drunk, it extinguishes the heat of digestion original: "digestionē," viewed by medieval doctors as a "cooking" process in the stomach requiring heat. It also disrupts the food and generates a sediment than which nothing is worse. However, if it is impossible to avoid drinking water—either because of heat in the stomach or the liver, or even due to the heat of the air—let the drinks be small, clear, and very cold.

24.

On the manner of sleeping and the customs to be observed

When you have been refreshed by a meal, lie upon soft bedding. Then sleep for a moderate amount of time. Rest for one hour upon your right side, then turn to the left and complete your sleep on that side. This is because the left side is cold and therefore requires greater warming. Know also that sleeping before a meal makes the body lean and dries out its moisture original: "humiditatem," referring to the radical moisture necessary for life; but sleeping after a meal restores and fills the body. Take care not to eat again until

you know most certainly that the stomach is empty and purged of the previous food. You may recognize this through the desire to eat and by the thinness of the saliva running into your mouth. For if anyone takes food without bodily necessity and without the desire to eat, he will find his natural heat original: "calorem naturalē," the internal heat that medieval science believed powered all bodily functions to be as if frozen or sluggish. If, however, he takes food when he has a desire for it, he will find his natural heat to be like a kindled fire.

When you begin to have a desire to eat, eat immediately. For unless you eat quickly, the stomach is immediately filled with bad humors original: "humoribus," the bodily fluids (blood, phlegm, yellow bile, black bile) that governed health which it draws from the waste products of the body. Then the brain is disturbed by the worst vapors; and when food is taken afterward, it becomes lukewarm, is tainted by those humors, and does not benefit the body.

If, therefore, you feel heaviness in your stomach and belly, then medicine is necessary for you. Therefore, place a warm and heavy shirt over your belly, or embrace a warm, beautiful girl Medieval medicine often recommended the proximity of another person's body heat as a gentle way to aid a "cold" stomach. If you feel a bitter belching, it is a sign of coldness in the stomach. The medicine for this is to drink warm water with oxymel original: "sirupo acetoso," a medicinal syrup of honey and vinegar or to vomit. For the trapping of corrupt food in the belly is the destruction of a strong body. And movement before a meal excites the heat of the sto[mach]...