(RNS) — There are two ways to know that the liturgical season of Lent is upon us here in America: One is that supermarkets, somewhat antithetically, come alive with outlandish foil-wrapped Easter eggs, Easterized versions of popular candies — I’m looking at you, Sour Patch Kids Easter bunny gummies — and displays devoted to Easter (and Passover) dinner staples.

The other is the proliferation of fish sandwiches on fast-food menus, a phenomenon that runs counter to everything we know about commerce and the decline of church attendance and personal piety in the United States.

For centuries, the Catholic Church used to forbid the eating of flesh meat on Fridays year-round, in weekly recognition of Jesus’ sacrifice. Following Vatican II-era reforms and a 1983 change to canon law, the U.S. bishops’ conference clarified that Catholics should fast and abstain from meat on Ash Wednesday and Good Friday and abstain from meat on the intervening six Fridays in Lent.

These practices led to the invention of McDonald’s iconic Filet-O-Fish sandwich, created to cater to Catholics. A McDonald’s franchisee in Cincinnati saw that he was losing business on Fridays and in 1962 petitioned founder Ray Kroc to add a fish sandwich to the menu.

The Filet-O-Fish was a hit and has remained on McDonald’s menus ever since. It’s not just that it gave customers a break from burgers, either: The corporation estimates that 25% of Filet-O-Fish sandwiches are sold during Lent.

This success continues despite the disappointing diminution of the Filet-O-Fish patty in recent years, topped with only a half slice of American cheese and a paltry squirt of tartar sauce. (I personally also lament the discontinuation of, in the Chesapeake Bay area, a special Filet-O-Fish with tartar sauce infused with the legendary local condiment, Old Bay.) 

But Lent is not only hanging on as an economic driver, its footprint seems to be growing. Wendy’s and Burger King reintroduced fish sandwiches this year. Popeyes, which found great success in 2019 when it challenged Chick-fil-A’s chicken sandwich hegemony with an offering of its own, has reintroduced its flounder sandwich, which debuted in 2021, this year during Lent. Popeyes and Long John Silver’s are also promoting $6 shrimp boxes.

Chick-fil-A, which has a famously strong evangelical Protestant ethos, only recently began offering fish sandwiches during Lent. But chains whose stores are concentrated in more densely Catholic areas include White Castle, which offers a Panko Fish Slider. Arby’s, 7-Eleven and Culver’s, which began in Wisconsin but is quickly expanding beyond the Midwest, also all offer fish sandwiches. (Of all the fish sandwiches I tried, Culver’s is my favorite — though as a Southerner, I’m still partial to Cracker Barrel’s Friday fried cod special, likely better than any Catholic parish fish fry you’ve ever been to.)

What’s most confusing about these commercial markers of devotion is that I see so little of it in daily life. When I was a kid, my dad recalled that in his childhood, public-school cafeterias had fish on Fridays to accommodate Catholic kids. Yet as an adult, I’ve rarely been aware of people actually keeping the obligation.

As a Protestant, of course, perhaps I wasn’t well positioned. Though Lent is said to be “trending among evangelicals,” according to articles in recent years in Christianity Today and other evangelical outlets, I was long taught to doubt its efficacy or legitimacy. As with so much else in Catholicism, I have since gained a respect for the church’s deeply traditional spiritual practices, but even among my Catholic acquaintances it seemed as if only the most devout actually observed, like going to confession. Indeed, in 2015, Pew Research Center reported that fewer than half of Catholics observed Lent by giving something up.

But fast-food menus this time of year clearly suggest something else is going on, as Lent has the power to modify some of the most scrupulously managed menus in the sector. In a highly consumeristic culture, people may not come to church or find time to express themselves through deprivation. But I can only conclude that, faced with a choice, people do make spiritual decisions about what they buy. Given the opportunity to think for a moment about Jesus’ bodily sacrifice, they remind themselves that it’s more than just food that sustains us.

(Jacob Lupfer is a writer in Jacksonville, Florida. The views expressed in this commentary do not necessarily reflect those of Religion News Service.)