Although medieval ideas about food were very different to our own, its importance was widely recognized. According to Galen, food “is probably the most important of all medical subjects,” and it dominated medieval regimens—many of which consist almost entirely of lists of foods and discussions of their properties and impact on the human body.

Article continues after advertisement

In order to remain healthy, it was important to know about the qualities of foods, which were categorized as hot/cold and wet/dry, with different qualities having different effects on the body, and bad foods leading to illness. The perceived connection between diet and health was underpinned by medical ideas about digestion, which was thought to be a three-stage process, similar to cooking, distillation and combustion. In the first digestion, which took place in the stomach and intestines, food was turned into chyle, with some superfluities being excreted through defecation. The second digestion happened in the liver, and produced blood, along with black and yellow bile (which were, respectively, stored in the spleen and the gallbladder). In the third and final digestion, the blood was spread around the whole body, providing it with the heat, moisture and vital spirits necessary for life.

Thanks to the English physician William Harvey (1578–1657), we now understand that blood circulates around the body, but medieval people believed that the liver was constantly generating new blood—so that digested food was incorporated into the body, and in a very literal sense a person was what they ate.

So, what did medieval people eat? Processed cereals such as pottage and bread were the key components of the medieval diet, although the quality of these foods varied with social status. Rich people ate leavened bread made from good quality wheat, while the poor usually had to make do with coarse, dense bread made from barley (which was cold and flatulent) or rye (which produced weak blood and little energy).

Nevertheless, it is clear that health was a consideration when preparing a meal.

Contrary to popular belief, medieval people also ate fruit and vegetables—though they were rather ambivalent about plants, and considered some of them to be downright dangerous. Brassicas (such as cabbage, cauliflower and broccoli) were an important part of the peasant diet, but caused both melancholy and nightmares; lettuce was dangerous because it was so cold and moist, while turnips and parsnips led to flatulence and lust. There was considerable wariness about beans, which were thought to cause flatulence and bad humours, as well as confusion, dizziness and general malaise; peas were more easily digested, and thus a much better option.

Similarly, some fruits were safer than others: citrus fruits improved digestion, especially in hot weather, while raisins were good for the stomach, lungs and liver. And nuts were nutritious and good for the brain.

But many common fruits, including apples, peaches and cherries, were viewed with suspicion, because they were cold and moist, and produced putrid humours. They could be made safer by cooking, and it is clear that many people did eat them. When Petrarch’s physician told him to avoid “apples and every kind of fruit from trees,” he declared himself appalled by “this scorn for the most beautiful things that at the same time delight the taste, the touch, the smell and the sight.”

The medical advice regarding animal produce was equally complicated. Butter was warm, moist and nourishing, and produced good blood, whereas cheese was a coarse food, hard to digest and likely to cause bladder stones—although a small piece at the end of the meal could improve digestion. Eggs were widely eaten, though the warm, moist yolks were healthier than the cold, moist white. When it came to meat, chicken was widely regarded as the healthiest option: moderately warm, easily digestible and extremely nourishing, it was especially suitable for the delicate stomachs of the wealthy and the sick. Pheasant and quail were less widely eaten but had similar qualities, though the latter was potentially dangerous because of its fondness for feeding on poisonous plants such as hellebore. Pork, lamb and mutton were all seen as nutritious meats, but beef was more problematic. It was cheap and coarse, produced thick blood, and was only really suitable for manual labourers. Duck, goose and venison were hard to digest, produced bad humours, and were best avoided by everyone.

But, in sharp contrast to modern ideas, it was cold, wet fish which was seen as a particular threat to health, because it generated large quantities of phlegm. It was, nevertheless, an important part of the medieval diet—partly for religious reasons, partly because it was cheap and partly because people liked it—and medical experts therefore suggested various ways to mitigate the health risks. Most methods aimed to warm and dry the fish, which should ideally be roasted or fried, rather than boiled—which would only make it wetter. Sauces and seasonings would also make it more fit for consumption.

Thus the physician Peter of Spain (who later became Pope John XXI) suggested that oil, vinegar, wine and spices should be used to “consume the moisture of the fish.” And Maino de Maineri warned that lamprey (which was “very dangerous,” though “tasty in the mouth”) should be killed by immersion in wine, prepared with a spicy jelly or bread sauce, and cooked very thoroughly.

Such recommendations reflected a wider belief that it was possible to make foods healthier through careful preparation and cooking—to the extent that some historians have suggested that medieval cuisine was essentially applied dietetics, with cooks using their knowledge of the properties of individual foods to produce healthy dishes. There is some evidence to support their claims: many recipe collections included dishes especially for the sick, and the famous fourteenth-century English cookbook The Forme of Cury was written in consultation with “maistres of physic.” But it seems likely that only the wealthiest households had access to such expertise, and there were always lots of other considerations at play, such as religion, display and taste.

Nevertheless, it is clear that health was a consideration when preparing a meal. For example, it was widely believed that cooking methods could change the properties of a food—so that beef, which was naturally dry, should be boiled (to warm and moisten the meat), whereas moist pork should be dried out by roasting. Most vegetables were dry, and therefore needed boiling, but onions—which were extremely moist—should be fried, to dry them out a little. Fruits were mostly moist, which was why it was safer to eat them cooked (preferably roasted or baked) and thus dried out.

Adding flavourings was another popular way to make food both healthier and tastier. Honey was the most common sweetener; its warmth and dryness meant that it was good for old people and those with cold complexions, although it could cause thirst, itching and stomach problems. Sugar was very much a luxury commodity, although it became more widely available from the mid-fourteenth century—and whereas we fret about the dangers of eating too many sweet things, medieval people focused on its warm, moist qualities (which made it good for the lungs, kidneys and bladder), and saw it as a healthy option.

But they shared our concerns about salt, which was used for seasoning but was also an important preservative for meat, fish and some vegetables. Warm and dry, in small quantities it could be a useful appetite stimulant and flavouring, but too much would dry the body, burn the blood, dry out the stomach, harm the eyes and brain, and cause itching. Consequently, cooks were warned not to oversalt food, and sometimes soaked preserved goods in water to remove the excess.

Herbs were also popular, and many offered significant health benefits. Parsley, for example, generated good blood and provoked urination and defecation; sage was good for the stomach and nerves, and mint warmed the stomach and aided digestion. And spices were much more widely used than we often assume, especially towards the end of the Middle Ages, as they became cheaper and more widely available; even in twelfth-century London, it was possible to buy flavourings such as pepper, cumin and saffron. Medieval elites were particularly fond of saffron (hot and dry, it comforted the heart and liver and aided digestion), while pepper (which was considerably cheaper and therefore more widely used) was very hot and dry, and good for stimulating appetite, improving digestion, dissolving wind and removing phlegm from the chest.

Furthermore, digestion was often compared to a cooking process—and just as it is important to follow the recipe when preparing a meal, this meant that foods must be eaten in the right order.

Many of these flavourings could be incorporated into sauces, which were extremely popular and had both culinary and medical benefits. They could stimulate appetite, plus they continued to heat food and to assist with digestion after it had been eaten. Sharp, vinegary foods were thought to be especially healthy, and were often used to tempt those with poor appetites to eat: the Salernitan physician Matthaeus Platearius (d. 1161) suggested that hard-boiled eggs chopped up and stirred into mint and vinegar sauce, or toast soaked in vinegar, were good for this purpose. And mixing could be used to modify ingredients, so that dishes which combined sweet and bitter flavours (such as vinegar and honey) were surprisingly common.

But this did not mean that foods should be carelessly combined. Medical experts had strong ideas about what foods could be eaten together. Although fish was often soaked in liquid before cooking, the encyclopaedist John Mirfield (d. 1407) warned his readers that they should not eat fish with milk or wine, because this could cause leprosy. They should also beware of mixing heavy and light foods, which were digested in different ways, so that combining them could lead to incomplete digestion and putrefaction.

Furthermore, digestion was often compared to a cooking process—and just as it is important to follow the recipe when preparing a meal, this meant that foods must be eaten in the right order. Maino de Maineri (who was writing for an extremely rich audience, his employers including several bishops, and the Scottish king Robert the Bruce) suggested that a meal might start with confections of pistachio, marzipan, candied hazelnuts or dates, to open the stomach. After this, dishes should be served in order of digestibility, from the easiest (such as a simple broth, which was hot and wet like the stomach) to the hardest (heavy fruits such as apples, grosser meats such as beef, or other risky foods such as eel or cheese). Further confections, such as candied ginger or spiced wine, could be used to close the stomach at the end of the meal.

There was also lots of advice about when a person should eat. From a medical perspective, the ideal was two meals a day, both taken between midday and nightfall, to allow the digestive process to be properly completed—and non-medics echoed this advice. For example, the grain merchant Paolo da Certaldo thought that a self-respecting man would eat only dinner and supper, because “This is how a man should live—eating at all hours is how an animal lives.” Similarly, the fourteenth-century French nobleman Geoffroy IV de la Tour Landry urged his daughters to form good habits which would stand them in good stead throughout their lives, claiming that “Taking refection once a day is an angel’s life, twice is a man’s life, but eating many times a day is a beast’s life.”

In practice, many people seem to have eaten three meals a day, especially towards the end of the Middle Ages, although breakfast was often relatively late by our standards. Indeed, many people seem to have gone to Mass or done some work beforehand; in August 1346, William Byschop, a Cambridge labourer, had already done a substantial amount of digging when he sat down at the bottom of a pit to eat his breakfast, and it collapsed in on him. Lunch, the main meal of the day, was usually eaten at around midday, followed by a light supper in the late afternoon or early evening. There is some evidence that people did eat at other times—snacking during work breaks, or in the evening—but this was frowned upon.

Nevertheless, the importance of moderation was clear, and most people recognized that eating only what you needed was good for both the body and one’s manners. Thus Hildegard of Bingen asserted that “someone who eats and drinks with moderation will have good blood and a healthy body,” while Peter Fagarola warned his sons “Beware of eating too much and too often, especially during the night.”

But how much food a person should eat could vary significantly throughout the year. For one thing, Christians were required to perform regular fasts, which usually meant abstaining from certain foods and/or restrictions on when one could eat, although especially devout individuals sometimes abstained completely. In thirteenth-century England, Christians were expected to avoid meat every Wednesday, Friday and Saturday during Lent (when eggs and dairy products were also forbidden), Advent and on some saints’ days (or the eves of their feasts) —although certain groups, including children, the sick and elderly, pregnant women and manual labourers, could be exempted.

Although it is easy to assume that such wealthy individuals were simply playing the system in order to indulge their dietary preferences, their claims were undoubtedly compatible with contemporary medical theory.

And the complicated relationship between food and bodily heat meant that everyone needed more food in the winter than during the summer months, and should alter their diet according to the season. Fortifying foods such as red meat were good in the winter months, whereas lighter, cooler foods such as young chickens and lettuce were best in the summer—and eating very hot foods could cause gout. For similar reasons, people who lived in cold places needed to eat significantly more, so that a Pole might eat more in a single day than an Italian would consume in half a week.

Matters were further complicated by the fact that custom, age and complexion all shaped what a person could and should eat. As John Mirfield wrote:

people are accustomed to dine four times a day, and yet are not harmed by it . . . others eat beans and tough and ancient beef; and some eat foxes and innumerable things of that nature, and yet they say that they are most healthy and keep well.

According to the widely circulated encyclopaedia On the Properties of Things, the best foods depended on the individual, “For many foods that are wholesome for a healthy man are poison to a sick man.” While a sad person should “eat a sufficient amount of food that agrees with him, so that he becomes invigorated anew from food,” overeating when happy turned “the humours that are in one’s blood . . . into the tempests of fevers.” Complexion also determined what a person should eat, so that (for example) garlic and pepper were good for the phlegmatic, but “venym” to a choleric person. A person’s age and occupation would influence their dietary requirements; in particular, sedentary individuals needed less food than their labouring counterparts, because “hete is strong in travailinge men and feble in restinge men.”

Doctors also suggested that no food would suit a person so well as that of his native place—so that many twelfth-century English soldiers died during Irish campaigns because of the “unaccustomed foods” and “change of diet.” When Gervase, a Durham-born cleric, became incurably ill while studying in Paris,

the collective opinion of all the doctors was that the sick man should go to his native land as quickly as possible, and there should, above all else, enjoy the foods on which he had been nourished from childhood. For . . . it was thought that the food on which invalids were brought up was more effective than any medicine.

Such considerations were taken so seriously that the Catalan friar Francesc Eiximenis (c. 1340–1409) complained that, if it was up to doctors, no one would ever fast or do penance; they encouraged their patients to obsess over their bodies to the detriment of their souls. People used medical advice to make excuses for themselves, claiming that “doctor’s orders prevent me from eating more abstemiously” or “if I don’t eat well, I’m not good for anything.”

His point is borne out by the evidence of the papal registers which (especially towards the end of the Middle Ages) were littered with dispensations to high-status individuals such as Humphrey, duke of Gloucester, who in 1434 was allowed to perform alternative works of piety when “he cannot fast on account of his health.” As early as 1248, Alexander II of Scotland (r. 1214–49) was permitted to break the Lenten fast “by the advice of his confessor and physicians”; two centuries later, James III (r. 1460–88) was allowed to eat “flesh, eggs and milkmeats in Lent and on other forbidden days,” “the eating of fish being very harmful to his health.” In 1481 Edward IV of England was granted his own dispensation, “the pope having learned that fish is injurious to his health, and that if he made a long use thereof his life would be in danger.”

Although it is easy to assume that such wealthy individuals were simply playing the system in order to indulge their dietary preferences, their claims were undoubtedly compatible with contemporary medical theory. St Thomas Becket cured several people who became ill after eating fish, including John (a Pontefract monk with a “young and sickly” complexion, who was thus unable to tolerate the salmon that was a staple of the monastic diet) and Juliana, a new mother sickened by overindulging in “some harmful fish.”

And some rich people did take their diets very seriously. Edward IV’s court physicians were reportedly required to “stand muche in the kynges presence at his meles, councellyng his grace whyche dyet is best” and around the same time, the duke of Burgundy employed six physicians to perform the same task. The wealthy were also very aware of the risk of poisoning; as well as rejecting anything which smelt or tasted bad, they might use emerald, coral and ruby (which were all thought to change colour if poison was present) to identify dangerous dishes. If the worst happened, cures for poisoning mostly aimed to provoke vomiting, sometimes followed by phlebotomy a few days later.

__________________________________

From The Medieval Guide to Healthy Living. Used with the permission of the publisher, University of Chicago Press. Copyright © 2026 by Katherine Harvey