It’s Lent and suddenly the fast food chains in America are fishing for the Catholic customer.

The convenience food giants learned long ago that on Fridays during Lent Catholics are not buying hamburgers, hot dogs, pork sausages, pastrami, pepperoni, and baloney, barbecue, chops, subs, ribs, steaks and chicken.

In fact it was the Catholics of Cincinnati, Ohio who helped bring about the famous Filet-O-Fish sandwich. In the early 1960s, a McDonald’s franchise owner, Lou Groen recognized that his sales were floundering on Fridays in Lent. Eighty seven percent of his customers were Catholic.

The 1960s were early days for McDonald’s and Groen was struggling to make ends meet. So he cast around for a new idea, and spotted that another restaurant was reeling in his missing Catholic customers by selling fish.

So he put some fried fish in a bun, added cheese and tartar sauce and put it on the menu. After a successful trial run he went to headquarters in Chicago and took the idea to McDonald’s founder and CEO Ray Kroc.

Groen recalled the conversation later, “I told Ray Kroc about the idea and he said, ‘You’re always coming up here with a bunch of carp! I don’t want my stores stunk up with the smell of fish!’”

It turned out Kroc had other motives to be pessimistic about the fish sandwich. He was trying to hook people with his own no-meat alternative-the “Hula Burger”-which was a slice of fried pineapple in a bun.

So the next time Lent rolled around, Kroc and Groen had a competition to see which was more popular-the Filet-O-Fish or the Hula Burger. The final score was Filet-O-Fish, three hundred and fifty. Hula Burger six. Customers who tried the Hula Burger said, “I like the Hula, but where’s the burger?”

By 1965 the Filet-O-Fish had a permanent place on the McDonald’s menu. To attract the Irish Catholics the franchise even ran an ad campaign featuring a jaunty cartoon fish named Phil A. O’Fish who sang a catchy little tuna.

Groen’s entrepreneurial initiative has been so successful that now the other major fast food chains also troll for Catholic customers. A whole grouper them have joined in. Wendy’s, Hardees, Chick Fil A, Arby’s and Burger King all feature fish sandwiches during Lent. The Fellowship of Catholic University Students have published a consumer report on which fishy fast food is best.

It’s a global phenomenon. In London you can skate across to your local McDonald’s and get a Fil-A-O-fish for just a couple of squid.

The takeaway from this story must be the realization that Catholics, if they got united, could have some serious consumer clout. If we were ever to discover the true power of our pocketbooks, we might be able to change more than a McDonald’s menu.

We should mull it over. Who knows? If we asserted our financial mussels in the cause of justice we might discover much more than the piece of cod that passes all understanding.