Saturday, September 25, 2010

The 10th century nun diet

A lot of intelligent people know more about diet and nutrition than I do, so I will merely comment on the following information from Jonathan Jarrett's blog.  It seems there is a forged charter that gives the total amount of food supposedly consumed by nuns in  a monastery with a certain number of nuns in it.  Divide one dicey number by another dicey number and you get what supposedly was the daily intake of the ninth or 10th century nun:

  • 1,440 g of bread
  • 1.38 l of wine
  • 70 g of cheese
  • 133 g of dry vegetables
  • 16 g of salt
  • 0.6 g of honey (which I guess was used in accumulated dollops)
Verdon (or perhaps Rouche) [scholars Jarrett has consulted]  calculates that this is 4,727 calories and says that the required daily intake is 2,400. That was France in 1975, and a rapid websearch suggests that UK women are advised by the National Health Service to keep calories down to 2000 a day. Of course, there is a big difference in how many calories the nuns were burning in just not freezing for at least half the year, but Verdon is presumably still right when he observes that this diet was seriously lacking in protein and vitamins.
So what do you say, informed eaters?

PS:  Historians of earlier eras are often forced to look at documents that were forged by institution trying to nail down what they thought were their historic rights.

Image:  Escapee nuns eating fast food.


  1. The bread certainly sounds too high - the average military number is 1/3 of a 1kg loaf per person, at least in France.

    Also, I personally would be interested to see a nun down the equivalent of nearly 2 bottles of wine by herself!

    I think the fact that the charter was forged is the first problem, which means we have no idea whether that was an ideal, an exaggeration, a number pulled from thin air, etc. That invalidates the mathematical exercise, although it's a interesting one.

  2. I agree with Cushing -- seeing a house of nuns each drink close to two bottles of wine a day would make for (if nothing else) an entertaining spectacle!

  3. What else would they drink?

  4. Anonymous3:05 pm

    Wasn't it traditional for these institutions to donate their leftovers to the poor? Perhaps these numbers were made with that in mind, that they wanted enough food to not only feed the nuns, but the poor as well.

  5. They surely had a garden and orchard for fruit & veg. Thus, pick-it-yourself stuff didn't have to be written down.

  6. To analyze if this is a sound diet is so full of land mines we will all blow up. We have no idea of the alcohol content of the wine. It is my understanding that modern wines have much higher alcohol (and thereby calories) than older wines that were used for regular drinking. We don't know how active the nuns were. Manual labour - cooking, cleaning, gardening etc. etc. can burn a lot of calories. The magical 2,000 calories for modern people is based on a life with washing machines, cars, running water etc. etc.
    We also don't know the time of the year when this diet is intended for - winter or summer. Was this perhaps a base diet for which fresh food and meats or fish would be added as available.
    Regarding a lack of protein this diet has over 100 g of protein potential as cheese is high protein (probably 14 g in this serving) but bread can be 5 to 10 g per 100g (again we know nothing of the nature of the bread) so that could be 70 to 140 g of protein from the bread alone. That is a lot if protein. My biggest concern would be lack of variety and the potential lack of minerals and vitamins but there is not enough information here to even venture down that path. I hope that helps.