The Real Reason Christians Eat So Much Fish During Lent

With Lent having begun for the Western Churches on Wednesday, February 17, Catholics will now be turning to fish every Friday until Easter. This, as CBS Minnesota explains, is due to a rule instituted by Pope St. Gregory the Great who held his office in the final decade of the sixth century. The rule stated that Catholics would eat neither meat nor flesh during Lent, expanding the practice of fasting on Fridays for a 40-day period.

Michael Foley, an associate professor at Baylor University, told NPR that the reason why fish is allowed when beef is not is that the edict singled out warm-blooded animals: "If you were inclined to eat a reptile on Friday, you could do that, too." Then, the tradition focused on eating fish on Fridays to commemorate the crucifixion. 

Almost 1,000 years later, when Henry VIII split from the Catholic Church in order to get a divorce and marry Anne Boleyn, the eating of fish during Lent took on a Catholic subtext, as Mental Floss writes. Although Henry's son King Edward VI attempted to encourage eating fish when the fishing economy eventually started flailing, the religious dimensions of why Catholics, in particular, eat so much fish had already taken shape.

In the Eastern Orthodox Churches, the dietary renunciations during Lent, Advent, the Apostles Fast, the Dormition Fast, Wednesdays, and Fridays go further than meat and flesh to include fish as well. In fact, Greece-Is lays out the usual fasting, which includes abstinence from meat, dairy, eggs, and fish, and the stricter fasting days, which prohibits oils. Shellfish is allowed, for some reason.

With such religious strictures over what one should eat when, it should not surprise that Greece is also one of the countries to fuel the Mediterranean diet. The Mediterranean diet, as Healthline describes, broadly consists of fruits, vegetables, legumes, olive oil, and, of course, seafood. While the purpose of Lent is not to set a health fad but to push the participant along their path, the limitations it sets does dovetail neatly with a regimen for a healthy lifestyle.

While the popularity of fish during Lent may have roots in a religious edict, it also paved the way for a truly modern creation: the Filet-O-Fish. According to USA Today, in 1962, a McDonald's owner in Cincinnati, Lou Groen, first came up with the fish sandwich to make up for the lack of hamburger sales during Lent for his mostly Catholic customers.