“And over here,” Dad pointed ahead, pausing for effect, “Is where the first Olympic Games were held.” Eleven-year-old me looked at the dusty field in Olympia, Greece, some rubble piled into columns. “I miss McDonald’s,” I said. No golden arches were to be found in 1984 among the ancient temples. “I bring my kids to Greece, and all they want is fast food,” my Dad lamented.

All demand and no supply makes for cranky kids — and consumers. Though I grew up working at my Dad’s 20-plus restaurants (including “B’s Beefy Burgers”) I did the unlikely at 18: I went vegetarian. I’ve been waiting for a plant-based burger from McDonald’s ever since.

Now multiple plant-based alternatives are competing for the mass burger market, and they’re gaining steam. The stock for Beyond Meat, set to drop its first earnings report as a public company on Thursday, has soared. It’s not just vegetarians and vegans who demand plant-based foods. Take the rise of plant-based milks: nearly half of all shoppers in the U.S. now buy plant-based milks, and according to a recent survey by Comax Flavors, 96% of the 1,000 surveyed who regularly use nondairy products were not vegan.

Having organized four monthlong citywide vegan challenges in the foodie city of Durham, N.C., where chefs said vegan was not in their Southern “flavor profile,” I can speak to the shock restaurateurs experienced from the resulting demand for plant-based meals after the challenge. We surveyed participating customers, and over half were not even vegetarian or vegan. One chef said, “The overwhelming response … propelled us to offer day-and-night options.”

Similarly, plant-based meat is on fire: Beyond Meat shot up 163% in price on its first day of trading. Burger King is adding the Impossible Foods burger nationwide. Restaurant Dive reports that White Castle beat its goals for Impossible Slider sales, while Tim Hortons recently started testing out Beyond Meat sausages. Arkansas-based Tyson Foods is creating a plant-based protein they project to be a “billion-dollar brand.”

Economic demand is a pretty basic principle: It’s a consumer’s desire to purchase a specific good (and the higher that demand, the more they will pay for it). Yet surprisingly, McDonald’s is ignoring it. After the annual shareholder’s meeting last month, CEO Steve Easterbrook said, “The question is: Will the demand make absorbing it worth the complexity?” Previously he wondered if adding a plant-based menu option was “worth it," and the company is so far only selling plant burgers in Germany.

I encourage McDonald’s to embrace consumer demand for both plant-meats and humane policies for animals. Unlike Burger King, which has also committed to a meaningful animal-welfare plan, McDonald’s has failed to adopt such a plan for the millions of chickens in their supply chain, condemning the birds to develop unnaturally fast in crowded, dark warehouses. Here, too, McDonald’s lags behind competitors.

To be sure, animal-based agriculture is a huge part of our economy. Yet, in an era where animal farmers have successfully transitioned from confining animals to growing vegetables, mushrooms, or using land for wind or solar farms, it’s not only possible, it’s smart business.

It’s time for McDonald’s to acknowledge demand and embrace the future of protein. Might I suggest Beyond Meat, or adding veg-chicken like KFC is considering? Humane plant protein is in. Resource-intensive animal confinement is as ancient and outdated as those stone columns my family visited in Olympia.

Eleni Vlachos is a drummer for Beloved Binge, writer at You Big Talker, filmmaker, 1/2 Greek, part-time manager of communications for the Social Intervention Group, volunteer for The Humane League, and a newish South Philly resident.