Capitalist agriculture has found the best spot to store its surplus in the bodies of workers.

It happened last summer without much media fanfare: Mexico surpassed the United States as the fattest country on earth. Though seemingly cause for U.S.-American joy, these days even the loss of negative American exceptionalism is too demoralizing to celebrate. Or maybe it wasn’t widely discussed because it wasn’t achieved by some massive weight loss in the U.S., but a shockingly fast growth in the overweight population of Mexico.

Whatever the reason for the lack of coverage, the fact puts some claims about the U.S.-American “obesity epidemic” permanently to rest. It is not rooted in some shift to sedentary middle-class labor, excessive driving, and too much sitting: A much higher percentage of Mexican workers still work in primary production or agriculture, while many fewer own cars. Obesity there can’t be blamed on a so-called culture of laziness and excess à la Wall-E’s floating invalids: claims centered on specifically U.S.-American attitudes to work or disposable income level must be chucked. So what has caused this massive rise in Mexican BMI?

The most scientific answer: no one knows for sure. As public health methodologies, data collection, and scrutinizing organizations proliferate, it becomes clear that when it comes to tracing an illness there are almost always too many factors—environmental, genetic, cultural, political, and psychological—to ever locate simple cause and effect. That is particularly true when tracing phenomena across long periods of time through large populations (in this case, a decades-long process across a nation of 120 million people). If this is true for even more directly diagnosed diseases, the complications practically become fractal when addressing “overweight/obese” populations, as body weight is an almost sublimely arbitrary, politicized, and medically indeterminate measure of health.

The simplest answer, however, is NAFTA. One of bipartisanship’s great achievements, negotiated by George H.W. Bush but signed by Bill Clinton, the North American Free Trade Agreement went into effect in 1994. Ending all tariffs between Mexico and the U.S., within a decade NAFTA both increased the flow and reversed the balance of trade between them. Mexico had a long-standing trade deficit with the U.S., mostly importing consumer goods. But after NAFTA’s passage, Mexican industrial production for U.S. markets exploded and a trade deficit became a moderate trade surplus. Of course, this manufacturing appeared because factories were ripped out of the unionized American heartland and transformed into sweatshops across the border (one reason why conservatives blaming Mexican migrants for white working-class joblessness is comically backward).

But in exchange for increased exports and the resultant GDP bump, Mexico essentially renounced its food sovereignty. Mexico is the homeland of corn. It’s where maize was first domesticated, and for millennia corn has been the backbone of Mexican food culture. Until NAFTA, a non-industrialized agrarian hinterland was supported by strong protectionist food policy, which had meant that Mexico maintained the bounty of maize’s evolution, with 59 distinct local breeds. Maize biodiversity had flourished in Mexico in the face of genetically modified corn monocultures to the north, and small subsistence farmers, many of them indigenous, made up much of the Mexican population outside the cities.

NAFTA spelled the end for all those protections, and U.S. corn and soy products flooded Mexican markets. The resultant drop in Mexican crop prices has dramatically accelerated the ongoing collapse of small Mexican farms, increasing rural proletarianization and urban migration. But these cheap products didn’t just shut down farms and swell Mexico City’s slums. Studies by the liberal Institute for Agriculture and Trade Policy (IATP) show that the rise in obesity correlates exactly with NAFTA, that NAFTA’s trade liberalization lead to a proliferation of cheap processed meat, soda, sugary drinks, animal products, fats, and sweeteners in Mexican stores and homes. As the IATP’s Dr. David Wallinga argues, “What people eat depends heavily on what food products in their immediate environment are easiest and most accessible.” The availability of cheap food led to more Mexicans adopting unhealthy diets, and, eventually, a public health crisis.

At first, this argument about the “foodscape” seems like a welcome relief from the moralistic diatribes focused on personal choice, self-discipline, and exercise that make up the general cultural conversation on food and obesity. Such individualist snake oil is perfectly embodied in government programs like Michelle Obama’s “Let’s Move!” campaign, which aims to end childhood obesity by encouraging more physical activity in children and teenagers. From “Let’s Move!” to consumer devices like the Wii Fit to the massive success of questionably effective programs like Weight Watchers, fatness is seen as an individual failing that can only be solved by personal discipline and sacrifice.

But all of these state initiatives and lucrative businesses are built on the presumption that being fat is bad, both morally and medically: a presumption with shaky scientific ground and a relatively short history. For most of the 19th century, in America plumpness not only indicated health, wealth and leisure, it was the definition of attractiveness. But the rise of railroads, refrigeration, and techniques increasing farmland productivity in the 1880s-90s meant more people had access to more food. Thickness began to lose its power as a sign of wealth with the widening girth of the working-class. Predictably, fatness also lost its place at the top of the beauty hierarchy. By the 1920s, the rail-thin flapper was the definition of modernity and sexiness.

Concurrent with its desexualization, fatness was pathologized as a health concern. Important activist and academic work has been done demonstrating that “obesity” is not a medical category at all, but rather a device for shaming and domination. As Pat Lyons argues in “Prescription for Harm,” the scientific evidence on “obesity” being a medical problem is at best dubious and at worst bunk. The supposed deadliness of obesity—you still occasionally hear the statistic that it kills 300,000 people a year in the U.S.—was constructed when the dieting industry purposely misconstrued a single study from 1993 whose authors have since consistently and publicly objected to its misuse, to no avail. Studies directly linking being overweight to negative health outcomes are significantly less consistent than those connecting negative health outcomes to smoking, psychological stress, racial discrimination, or poverty. The evidence that losing weight in and of itself has good health outcomes, meanwhile, is so contradictory as to be non-existent, while weight-cycling and constant dieting in an attempt to lose weight have been rather definitively connected to increased blood pressure, depression, and eating disorders. But, due to the incredibly lucrative dieting industry (in 2013, it was estimated at $61 billion, or twice the size of the U.S. film industry) embedding itself through lobbying, placement in public health agencies, and extensive marketing both to consumers and doctors, there has been a generalized cultural pattern toward “exaggerating the health consequences of higher weight while downplaying treatment failure.” Thus we are left with warnings of an “obesity epidemic” that afflicts over 70 percent of the population.

Even if the stigma connected to fatness is totally politicized, even if most of these overweight people’s health outlook actually has little to do with their body size, something needs to explain the (undeniable) rise in BMI. And so, as in the IATP study, over-production and general availability of cheap calories becomes the liberal consensus explanation for the “obesity” epidemic in both the U.S. and Mexico. Supported by wildly protectionist subsidies from the federal government that mean agribusiness will always make more money if it grows more food, buoyed by marketing (which has been shown repeatedly to directly affect the amount people eat) and lax regulation, the argument goes, cheap food is just too readily available.

The argument isn’t entirely wrong. But if this flood of cheap food was always available as a strategy to agribusiness—subsidies go back to the New Deal, after all—why has it only emerged in the last 40 or so years? And why has the market in cheap food also meant a general fattening of the population? Fatness, as it is currently constituted, has to be understood not purely as a question of overproduction, but as one of the “spatial fixes”— the process of opening up new markets to capital in new territories—to the general crisis of underconsumption and falling profits that capital has faced since 1973.

There are, in theory, limits to how much food you can sell to a population. Any food market will hit the ceiling of “inelastic demand.” With the technological intensification of farmland productivity—through labor-cutting industrialization, GMOs, pesticides, fungicides, and food substitution (like corn syrup for sugar)—businesses can produce almost limitless varieties and amounts of food as long as they have somewhere to sell it and someone to sell it to. Throughout the 20th century, U.S. imperialist strategies in Central America (like United Fruit), its wartime agricultural support for allies, and even its humanitarian food aid were all designed to open up new food markets. NAFTA is another perfect example of such a spatial fix: It both reduces the cost of labor and creates new customers for their product. But there is another spatial fix that agribusiness has stumbled upon, one that has little to do with borders. Space has been opened up in the actual bodies of workers.

As Julie Guthman argues in “Neoliberalism and the Constitution of Contemporary Bodies” (from The Fat Studies Reader), cheap food and fat people perfectly solve the problem of agricultural production outpacing demand. Guthman explains: “Not only does [fast food] involve the super-exploitation of the labor force, but it also provides an outlet for surplus food. Insofar as this surplus manifests in more body mass, the contradiction is (temporarily) resolved in the body.” As long as people get fatter, they can continue to eat more food, incubating the market in their bellies. What about when people reach a material limit of their fatness, deciding they want to lose weight or eat more moderately? Agribusiness has got that market covered too, selling faux foods like Diet Coke and Splenda. “This double fix of eating and dieting, in other words, is not epiphenomenal; it has become a central piece of the U.S. economy,” according to Guthman. The market literally expands with waistlines, but when the waistlines contract, a market grows there too.

Of course, certain bodies are more prone to these techniques than others. Fattening-as-market-expansion happens disproportionately to the poor, women, and people of color. The rich are afforded the right to buy both food and thinness, while the poor afford only calories. But calories are not food, and food is not reducible to calories, unless you’re selling it. Cheap corn, soy, and animal product-intensive foods have very low nutritive value, so a person has to eat way more of them to get the same nutrition. Cheaper calories mean fatter bodies, not wallets.

Thanks to the massive social stigma produced by a century of public health misinformation, a shame-based culture industry, and health care professionals (mis-)trained to recognize body size as a health indicator sui generis, over 70 percent of the U.S. and Mexican populations are made to feel intense body hatred (though it’s plausible that the other 30 percent feel some too). This drives them further into the beauty and diet industries, which provide the same “weight loss” solutions they’ve pushed for 40 years, despite those “solutions” having upwards of a 95 percent fail rate. Guthman describes this as structurally bulimic: an entire market built like an eating disorder. Consumers ping-pong back and forth between food and diet, giving both industries yet more money and yet more power to place their scientists at the head of public health institutes and continue to push their conceptions of obesity and health on an increasingly overweight and self-loathing public.

NAFTA didn’t merely open Mexican markets to cheap calories, but to an entire nexus of products. The pharmaceutical, fitness, and “health and wellness” (e.g. low fat) food industries are growing dramatically in Mexico. The markets opened up by these industries in turn benefit off of the dysphoria produced by a cultural aversion to fatness, an aversion that the U.S. also exports. One 2012 study found that, controlling for all other factors, there was a direct correlation between weight gain and time spent in front of English-language U.S. television among children in Baja, Mexico. The U.S. exports both fatness and anti-fatness, and does so both materially and ideologically. Neoliberal ideologies of personal responsibility and market solutions seal the deal, leaving fat people blaming themselves for their structurally-produced fatness while throwing money away at both shitty food and shitty “health” solutions.

What would a collective response look like? On the production side, Mexican farmers have organized against GMO foods, though these struggles have often focused on petitioning the government for a return to historical protections. While CSAs, “locavorism,” and farm-to-table food are more often than not a part of gentrifying projects, campaigns defending community gardens and urban farms can become nodes of resistance where the fight for food autonomy and struggles against urban development meet. Meanwhile, many fat activists have worked to destigmatize fatness, though their work is often stymied by recuperation on the one hand and the knee-jerk (diet-industry produced) assumption that being overweight actually is bad for you on the other. Queer and anti-racist practices that celebrate otherwise marginalized bodies (as opposed to the mass-culture fetishization of “bears” or big asses on otherwise skinny women) also offer potential first steps.

Food autonomy, a total reevaluation of health and beauty standards, and a non-disordered cultural relationship to food, however, will require more than just the sum of such (important) struggles and interventions. The “lank, narrow-chested, hollow-eyed ghosts” that Engels observed in working-class London still haunt the salvage-heaps, slums, and sweatshops of the world. But increasingly, much of the global proletariat is fat. Not merely working at the behest of the market, their bodies have become literal geographical expansions of it. That a particular way of eating is now a part of their labor makes them no less well-positioned to destroy capital through their organized refusal to work. The workers have nothing to lose but their pounds.