Sorry, you need to enable JavaScript to visit this website.
About the Foundation

Lean days and fat days

According to tradition, Christians had to obey food restrictions in order to do penance. Meals were governed by alternating ‘fat’ days and ‘lean’ days. On certain days, meat was forbidden and replaced by fish. Fish farming and preserving methods developed to meet the needs of practising Christians.
Diego Velázquez, Christ in the House of Martha and Marycirca 1618, oil on canvas, National GalleryLondon

Lean days

Unlike some other religions, Christianity does not forbid any specific type of food, however it imposes dietary restrictions. From the beginning of Christianity, in contrast to ‘fat days’, there were days of fasting or days without meat, called lean days. These days of fasting were the opportunity to do penance and to commemorate the important moments in the life of Jesus or of certain saints. They varied across different eras and regions. Lent was the longest period of fasting, and the period of Advent also included certain lean days each week. Depending on the era, every week of the year had at least one day of fasting: usually Friday and sometimes Wednesday or Saturday. The eve of major festivals was also an opportunity to fast. The Christian calendar had between 150 and 250 lean days, thus, in extreme cases, there were only 100 days on which people were able to eat without restriction. In the 16th century, the Reformation ended the practice of fasting for protestants and, over the centuries, it gradually became less restrictive for Catholics. Since the mid-20th century, only two days of compulsory fasting remain: Ash Wednesday and Good Friday.

From meat to fish

Meat was long seen as highly desirable food with undeniable nutritional values. As the restrictions had to apply to a highly-valued foodstuff, meat and animal fats (such as bacon and lard) were therefore forbidden on lean days. By contrast, fish was not forbidden, as it is cold-blooded and was therefore considered to be different from land animals. Fish was included on the menu on lean days, at least for those who could afford it. The fat and lean dilemma did not concern the poorest members of the population, who were used to a pulse-based diet.

Strategies around fish

For regions located far from the sea, rivers or lakes, provision of fish proved problematic. In the Middle Ages, monasteries began to develop fish farming, in order to meet the growing demand for fish during lean days. Carp, pike, trout and perch were farmed in ponds. It seems that eating fresh fish throughout the year remained a privilege for rich people. Preserving techniques were developed such as drying, smoking and salting. Cold-water fish, such as herring and cod, were found in regions of Europe far from where they had been fished. The custom of eating fish on Fridays has not completely disappeared.

The revenge of fat

Fat days were a strong contrast to lean days. They were an occasion to feast joyfully and abundantly. Shrove Tuesday, the day before Ash Wednesday, was, and still is, a time for eating rich food, such as pancakes and doughnuts.