Meatless Monday has been getting an awful lot of attention lately, with Oprah’s vocal support and the food services giant Sodexo’s rollout only the most recent examples. But what is Meatless Monday, really? Is it a rallying cry for health, a food marketing ploy, a blogger-led viral movement, a student activist cabal, a celebrity-driven bandwagon, an environmentalist’s dream, or a meat packer’s nightmare? I’d say it’s a little bit of all of these things and perhaps that’s its appeal.

Launched in 2003 by founder Sid Lerner and backed by Johns Hopkins Bloomberg School of Public Health, Meatless Monday has always been about health: cutting meat one day a week to reduce the risk of chronic preventable conditions like cancer, cardiovascular disease, diabetes, and obesity. In 2009, we extended our message to focus on the environmental as well as the health benefits. Michael Pollan went on Oprah on Earth Day that year and said his own family goes meatless on Mondays. That fall, the entire Baltimore public school system adopted Meatless Monday. More school districts, campuses, cities, restaurants, worksites, and other groups have followed suit.

But that only scratches the surface. What I find much more interesting, and revealing, is the fact that two years ago there was one Meatless Monday blogger–Kim O’Donnel–and now there are well over 150 who’ve started doing weekly Meatless Monday features. We get e-mails from groups and individuals all around the world hoping to join the growing international programs that already exist from Taiwan to Brazil to Canada. As we furiously tap away at our computers here at Meatless Monday’s headquarters in New York City, we’ve long ago come to realize this thing is way bigger than we are.

Why now? For one, it’s a pretty easy ask. It’s one day a week; it’s not veganism, nor is it even vegetarianism. It’s merely a suggestion to go plant-based on Mondays. That’s it. We keep the message intentionally simple, to make it accessible to all, in the hopes of reaching as many people as possible. In these polemical, partisan times, perhaps moderation is appealing. In that sense, we’re very much in line with the USDA Dietary Guidelines 2010, with its moderate message encouraging Americans to eat more vegetables and fruit.

Further, Meatless Monday is about choice. We encourage adopters, whenever possible, to serve meatless entrees alongside meat entrees. Recently, Bowdoin College held a Meatless Monday event, serving up tasty plant-based options to introduce students to the campaign. The organizers chose to offer only meatless options, and several students protested what they perceived was their power of choice being taken away. But we want to give people more options, not less. We’re all about getting people to try new healthy foods and veggie-based recipes. It’s not about taking away–it’s really about adding. That’s an American notion–combining democratic discretion and positive messaging–if ever there was one.

Also, we want this to be your movement. We’re fans of folks like Nicolette Hahn Niman who encourage consumers to eat less meat, but better (sustainably raised) meat. But we leave it up to our adopters to define Meatless Monday. We work with so many different groups–cities, schools, campuses, restaurants, worksites, chefs, dietitians–that it makes sense to allow each one to shape its message to its specific audience. This flexibility allows people to feel personally invested in our campaign (which is vital in building a national movement).

Perhaps the most important factor in the growth of Meatless Monday is, well, anxiety. There’s a lot of worry out there over large, looming crises: climate change, the obesity epidemic, food safety, environmental degradation, animal rights, budgetary woes, etc. Meatless Monday is a direct, personal response to these global fears, something we can all do that positively impacts these issues. In this way, we can tap into the energy and support of the many groups worldwide fighting these causes, making their platforms our platforms.

Experts are forecasting record U.S. meat prices on the horizon. At a time of high unemployment and economic uncertainty, that’s bad news for our meat-loving nation. Americans are going to have to start eating a little less meat. From this perspective alone, the time is right for Meatless Monday. Ultimately, after all the elaborate justifications and cross-competing agendas, Meatless Monday is about one simple thing: eating more vegetables. Isn’t that something we can all get behind?