Medieval scholars considered human digestion to be a process similar to cooking. The processing of food in the stomach was seen as a continuation of the preparation initiated by the cook. In order for the food to be properly "cooked" and for the nutrients to be properly absorbed, it was important that the stomach be filled in an appropriate manner. Easily digestible foods would be consumed first, followed by gradually heavier dishes. If this regimen was not respected it was believed that heavy foods would sink to the bottom of the stomach, thus blocking the digestion duct, so that food would digest very slowly and cause putrefaction of the body and draw bad humors into the stomach. It was also of vital importance that food of differing properties not be mixed.
Before a meal, the stomach would preferably be "opened" with an apéritif (from Latin aperire, "to open") that was preferably of a hot and dry nature: confections made from sugar- or honey-coated spices like ginger, caraway and seeds of anise, fennel or cumin, wine and sweetened fortified milk drinks. As the stomach had been opened, it should then be "closed" at the end of the meal with the help of a digestive, most commonly a dragée, which during the Middle Ages consisted of lumps of spiced sugar, or hypocras, a wine flavored with fragrant spices, along with aged cheese. A meal would ideally begin with easily digestible fruit, such as apples. It would then be followed by vegetables such as lettuce, cabbage, purslane, herbs, moist fruits, light meats, like chicken or goat kid, with potages and broths. After that came the "heavy" meats, such as pork and beef, as well as vegetables and nuts, including pears and chestnuts, both considered difficult to digest. It was popular, and recommended by medical expertise, to finish the meal with aged cheese and various digestives.
Terence Scully, Food in the Middle Ages,
10^ Scully (1995), pp. 135–136.
11^ Scully (1995), pp. 126–135.