In the last 20 years, the amount of local foods consumed in the American diet has tripled, according to USDA, and now comprises two percent of food consumed in the U.S. As with anything that’s popular, some have seen fit to tear it down. Why? Do they find the locavores annoying, or do they seriously believe, as many argue, that local food enthusiasts pose a threat to the planet?

Thanks to the farm-to-table movement, menus have become dense with information, as chefs detail the life histories of every ingredient in every dish. This focus comes increasingly at the expense of the finished product, according to food critic Corby Kummer in Vanity Fair. While Kummer has nothing against locally sourced foods—he’s a fan, in fact—he’s becoming weary of the “farmwashing” craze. He mentions a talented Silicon Valley chef, David Kinch, as an example of how less can be more. Kinch works closely with a local farm for much of his produce, but doesn’t gloat about it in the menu.

“You could appreciate the fact that many of the ingredients came from 13 miles down the road, or not. But you didn’t need to listen to a word about the farmer, or how his pigs went to Montessori school. That’s what the future of farm-to-table should be: food that speaks for itself without having to tell you where it comes from.”

A darker side of the exhausting menu trend was recently exposed in San Diego Magazine, which detailed cases of straight-up menu fraud.

“Sometimes it can be very blatant,” Tom Chino of the legendary Chino Farms told the magazine. “Chefs will come look [at what we’re selling that day], write down notes, leave without buying anything, and then say they’re serving our food at their restaurants.”

Meanwhile, another crop of opportunists is sprouting like weeds to jump on the local foods bandwagon in a much different way: by trying to tear it down. They’re portraying locavores as misguided at best. But to the extent that the doctrine might continue to spread, as actual threats to society.

In the book The Locavore’s Dilemma: In Praise of the 10,000-Mile Diet, economists Pierre Desrochers and Hiroko Shimizu argue that if everyone focused on local foods, agriculture would do more damage to the environment than it already does. Their case rests on a widely circulated statistic that many locavores might not want to hear: the transportation of food accounts for about five percent of food-related carbon emissions, while production can create a lot more. Thus, local foods can have a larger carbon footprint than imported foods, if the imports were grown in regions where they can be coaxed from the soil with less energy. Greenhouse tomatoes in the UK, for example, have been shown to produce three times the greenhouse gas emissions as tomatoes imported from Spain.

The well-rounded locavore would do well to consider such nuance. But at the same time, many things about this book make it seem more opportunistic than sincere. In an interview with Grist, Desrochers admitted to writing the book, primarily, “to save my marriage,” as opposed to, say, the world.

The impetus came, Desrochers recounted, when a visiting locavore gave a lecture in which he called Japan a parasitic society because it imports so much food. “My wife was born and raised in Tokyo. She made me promise that I would do something about it.” The book’s intro bluntly states the authors’ objective: To, “slaughter as many sacred cows in the food activists’ intellectual herd as we could.”

Similar arguments have been made repeatedly in recent years. Stephen Budiansky did so in a 2010 New York Times editorial "Math Lessons for Locavores," as have the books Just Food, An Economist Gets Lunch and Food Police.

These arguments, based on economic concepts like efficiency, comparative advantage and the economics of scale, assume that all advantages and disadvantages of a given food chain can be accounted for. But can they?

It’s often pointed out that local food is more expensive than imported factory farmed foods. Cheaper food leaves more money in the wallets of consumers to spend elsewhere, goes the logic. But when L.A. Times writer Isabella Alsobrook tried a 100-mile diet, she found that while the produce indeed cost more, she actually saved money overall, because by avoiding non-local foods she also avoided processed foods. She had to cook more from scratch, with fresh, local ingredients, and saved money. Most would agree that this is a healthier way to eat.

Taken to their logical extremes, the economics-based arguments would label most gardens as inefficient. And most gardeners would agree that it would be more efficient, and even cheaper, to spend a few extra hours at work and buy all their food, than spend that time crawling through the dirt. But they choose to garden just the same. Quality of life is hard to quantify.

A recent article by two economics professors, Anita Dancs and Helen Scharber, takes the efficiency arguments to task in the economists’ own language. While California can grow a lot of produce, they point out, the economic calculations don’t account for the state’s dwindling aquifer. Florida may grow cheap tomatoes, but the calculations don’t account for the near-slavery conditions in which the workers toil. Power imbalances, Scharber and Dancs note, aren’t incorporated into the 10,000-mile diet’s calculus:

“Looking through the conceptual lens of power relations—between agribusiness and contract farmers, farm owners and farmworkers, food corporations and low-income consumers, the government and immigrant workers—gives us a clearer picture of who determines what costs and benefits are created in the food system and how these costs and benefits are distributed. Paying attention to power allows for the possibility that the falling food prices attributed to comparative advantage and economies of scale may be related, instead, to the ability of the powerful to offload social and environmental costs onto the relatively powerless.”

“I can’t believe that people are trying to argue that communities feeding themselves is a bad thing,” said Josh Slotnick, a farmer in Missoula, Montana, when I confronted him with the efficiency arguments. He believes that unlike the 10,000-mile diet, the 100-mile diet is empowering to local producers, workers, consumers, and the communities they share. “Growing food in just a few places and shipping it around the world from there doesn’t sound like efficiency. It sounds like slavery.”

Slotnick acknowledges that some foods, like wheat, oranges or mangoes, can only be grown in certain regions. And he sees nothing wrong with shipping such foods to wherever they are needed. “But everyone should be growing vegetables. Everywhere.”

Eating locally, he argues, makes you a better citizen. “Food is a medium for creating culture. It’s a medium for people falling in love with their places. And when people love where they live, all kinds of great behavior follows, very little of which is economically rational. It’s a red herring to say that because the industrial food system is so efficient and its carbon footprint is so small that it’s a good thing. Agribusiness isn’t about making food and places better. It will make us better consumers, but not better people, or better citizens.”

Maybe the farmers market is not as efficient a source of food as a series of distant monocultures, but it’s a source of community, and entertainment. And even some economists will concede the point that local food, harvested at the peak of ripeness, will taste better. In "Math Lessons for Locavores," Stephen Budiansky admitted that there are "pleasures and advantages to the palate and the spirit of eating what's local, fresh and in season."

Anyone who’s raised chickens will surely concede it would be more efficient to buy eggs at the store. But try telling that to my two-year-old, whose first words in the morning are “get some eggs,” as he stumbles toward the coop. Should I tell him how inefficient that idea is?

I’ll let you try to do that, if it’s really so important to you. But I fail to see how he, or his locavore brethren, are harming anyone.