For a planet–healthy diet, try eating like a Benedictine monk

Before there were self-help guides or the printing presses needed to mass produce them, there were monastic rules. Unlike modern self-help guides, these manuals focused not on the self, but on how to live cooperatively while remaining in balance with nature. Among the most influential was The Rule of Saint Benedict, a 6th century guide to surviving in a monastery. While much of The Rule describes how to live your best austere life, 21st century readers will find surprisingly modern advice for sustainable eating. 

The Benedictines were not environmentalists in the modern sense. They had no conception of carbon footprints, biodiversity loss, or understanding of gut microbiomes. Yet necessity and discipline, and an abundance of green space, combined to produce a dietary pattern that many climate scientists and nutritionists would now applaud. 

For starters, the Rule was explicit about meat. “Except the sick who are very weak, let all abstain entirely from eating the flesh of four-footed animals.” In practice this meant a diet overwhelmingly based on grains, legumes and vegetables, with occasional fish, cheese and eggs. Beer and wine also featured heavily, though modern readers may wish to selectively follow this advice and remember that back then beer was safer than the drinking water. 

A typical monastic meal included two cooked dishes, usually a soup of garden vegetables alongside beans, with bread and seasonal vegetables or fruit. Monks were commonly allotted a pound of bread and a pint of beans a day. This bread was baked using locally sourced grains and kneaded by hand, which could mean that fewer of them suffered from gluten intolerances triggered by the industrially processed bread we are more likely to eat today.  

The medieval monastery garden was also far more diverse than the average modern supermarket shelf. Alongside onions, leeks, and cabbages grew spinach, lettuce and turnips. The monks were particularly fond of garlic, believing that it could ward of plague and reduce hunger. Leafy greens came in many forms: sea kale, sea beet, sorrel, spinach, and the wonderfully named Good King Henry. Carrots appeared in purple, yellow and white varieties rather than the uniform orange cylinders perfected by modern agriculture. Potatoes had not yet arrived in Europe, so monks relied on root vegetables such as parsnips and skirret –  a white spindly root vegetable that is now mostly forgotten. 

To bulk up gratins and soups, the monks relied heavily on broad beans. This is where medieval practice aligns strikingly with modern environmental science. Not only are these little beans a nutritional powerhouse, but they are also excellent for the planet. They enrich the soil by trapping nitrogen, thereby reducing the need for fertilizers; improve soil structure; and their flowers in early spring improve biodiversity by acting as pollinators.    

Skirrets, good for soups

Long before industrialisation began changing our planet, monks understood that eating seasonally and locally was good for their health and their local environment. By contrast, the modern global diet has become both environmentally costly and biologically monotonous. Three crops: wheat, rice and maize, now provide roughly half the world’s calories. Three animals: pigs, cows and chickens make up most of our protein. Supermarkets offer visual abundance while relying on a limited range of perfectly presented produce, most of which is not grown within 100 miles of where we’re buying it. Medieval gardens, by contrast, often contained dozens of edible species. For monks the word “imported” meant anything that could be transported by donkey cart before going off.  

Nutritionists increasingly argue that such diversity matters not only for ecosystems but for human health. Doctors advise people to eat a broad range of plant-based foods because the gut microbiome thrives on variety. The monks, without understanding microbiology, accidentally helped themselves further through fermentation. Medieval monasteries were centres of pickling, brewing and preserving. Fermented foods improve the diversity of gut bacteria, which researchers increasingly associate with lower rates of inflammation and disease. Fibre rich diets based on vegetables, pulses and whole grains provide the fuel these microbes need. 

The United Nations has meanwhile established dieatary  guidelines that would not surprise a Benedictine abbot. Animal based foods, especially red meat and dairy, generate far higher greenhouse gas emissions than most plant-based alternatives. Beef production in particular requires vast quantities of land, feed and water. None of this means modern consumers can simply replicate medieval monasticism. Eating locally in modern Britain is difficult, and for many prohibitively expensive. The economics of industrial agriculture often make imported food cheaper than domestic produce. Seasonal diets require more planning and flexibility than families with stretched time and incomes often have. Medieval monks also expended more physical labour than office workers and had lower life expectancy to boot (although their diets likely expanded their limited time on earth).  

Still, the broad lesson remains useful. Eat plants grown as close to home as possible. Eat what is in season. Waste little. Ferment and preserve when time allows. If you are going to eat meat, eat an animal that was raised in conditions that as closely as possible resemble those of a farm surrounding a Medieval priory. That advice resembles the famous maxim of Michael Pollan in his book The Omnivore’s Dilemma: “Eat food. Not too much. Mostly plants.” A Benedictine monk would have recognised the sentiment immediately. 

Next month we will be exploring more of the relationship between planetary and dietary health. On 22nd June we will host our Climate and Future of Health forum where will hear from food system’s experts on how to align modern diets with the sustainability of the planet. You can find more information and sign up here.  We will also be hosting an event on June 3rd on the biology of appetite. Information can be found here.