How many times have you checked a food package to see where it was produced, wondering about all the energy it took to get from the farm to your fork? Once an issue that few people pondered, the “eat local” movement has inspired conscientious consumers all over the country to contemplate how we can each do better by the planet at meal-time. The issue’s gone so mainstream that even TIME magazine published a cover story a few years ago entitled, “Forget Organic—Eat Local.”

Well, according to a recent Harvard Business Review article, we would be wiser to reconsider the amount of meat products on our grocery list rather than merely looking for how many miles our food may have traveled.

How much more concerned should we be? A lot.

The HBR cites a Carnegie Mellon study that concluded that we’d each do more good for the planet if we ate meat-free just one day a week than we would if we ate exclusively—100 percent!—local foods.

Why? In short, because it generally takes vastly more resources to raise animals than it does to produce plants. For example, The New York Times reports that, calorie for calorie, the production of meat requires 16 times more fossil fuel than vegetables and rice.

Those of us in the sustainable food movement should take heed of the words of people like environmental historian James McWilliams, who notes in his book Just Food, “to be perfectly blunt, if the world continues to eat meat at current rates, there’s simply no way to achieve truly sustainable food production.”

In other words, Carnegie Mellon’s research concludes that most animal farming (and slaughtering) is so environmentally taxing, we’d be better off simply opting for a once-weekly plant-based diet than getting every morsel of our food from the local farmers market. (Of course, eating plant-based foods from that local farmers market may be even better.)

This is one reason WorldWatch Institute reports, “It has become apparent that the human appetite for animal flesh is a driving force behind virtually every major category of environmental damage now threatening the future.”

The good news is that campaigns like Meatless Mondays are gaining popularity throughout the country. As well, it’s often easier to find a vegetarian option than a local option at nearly any restaurant.

Whether it’s to protect the planet, prevent cruelty to animals, or improve our health, eating lower on the food chain is a win-win. And with all the free tips and recipes for reducing our consumption of meat out there, it’s never been easier.

Perhaps it won’t be too long before we see a TIME cover feature beckoning, “Move Over Meat—It’s Plants’ Time in the Sun.”