[Epistemic status: The authors of this book make many factual claims that I'm not equipped to conclusively verify. Much of the publicly available information on the food industry comes from agribusinesses themselves or from activists who bitterly oppose them. In this review I've tried to summarize the authors' claims as they've presented them, with the occasional corroborating link, but as a layman I can't offer a much more complex perspective on these topics beyond what I learned from this book. The value judgments expressed in this review are my attempt to capture the authors' point of view, except where otherwise noted. I've absorbed many convincing arguments against factory farming from Effective Altruists over the years though, and as of this writing I've drastically cut back my meat consumption because of it.]

The Ethics of What We Eat: Why Our Food Choices Matter was published in 2006 and written by Peter Singer and Jim Mason. You’ve probably already heard of Singer, due to his enormous influence on the ideas and practices of Effective Altruism. (If not, his 1971 essay "Famine, Affluence, and Morality" is a good intro to his moral viewpoint.)

Jim Mason, meanwhile, is an author and attorney whose prior work focuses primarily on animal advocacy. The Ethics of What We Eat is actually the second collaboration between the pair; the co-authors connected in the ‘70s, after Singer published Animal Liberation, and in 1980 published Animal Factories, an exposé on the abuses of industrial farming.

In The Ethics of What We Eat, however, their aims and research are somewhat more sprawling in scope. While animal treatment and factory farming remain a major focus of the book, M&S also address the job conditions of food production workers, as well as the merits and demerits of specific subjects like organic farming, GMOs, Fair Trade certification, and "eat local" movements.

Mason and Singer present their research as a case study of three American families and their day-to-day food choices, each representing a certain set of popular American diets. All of the families are real people who cooperated with the authors’ research for several months; each main section of the book starts with a short segment introducing us to the family members and their life before diving into a farm-to-table examination of where their food comes from. (The authors mention that ~20 families expressed interest in their project, but only five or six stuck it out through the early phases. They settled on three relevant samples for the book.)

Lee and his wife Jake live in Arkansas with their two young children, buy groceries at Wal-Mart, and mostly visit chain restaurants or fast-food joints when they grab dinner out. Their meals are high in meat, dairy, eggs, and refined carbohydrates, and M&S use Jake and Lee’s shopping list to examine the "Standard American Diet."

When M&S follow Jake’s grocery purchases back to their source, unfortunately, they almost invariably lead back to a factory farm. These early chapters in the book are unsurprisingly the most macabre, dwelling on the pain and suffering that industrial farming inflicts to animals, workers, and to communities nearby. (At one point the authors even get hired as turkey inseminators, which they describe as "the hardest, fastest, dirtiest, most disgusting, worst-paid work we have ever done." It turns out to involve man-handling hundreds of panicked turkeys for over ten hours in a filthy room, dodging a spray of dislodged feathers and spurting birdshit the entire time.) They also visit an Iowa swine farmer, who gives them a tour of his facility. The pigs are fed antibiotics and kept in "total confinement," which means they never go outside. (The authors praise the farmer’s candor, but aren’t impressed with the living conditions on his farm. After they send him a first draft with their notes, the farmer discreetly asks not to be named in their manuscript. He’s referred to pseudonymously as "Wayne" in the book.)

The authors next examine the purchases of Jim and Mary-Ann, who hold white-collar jobs in small town Connecticut. Jim is vegetarian but his wife and daughters eat (mostly organic) meat and fish. They shop at Trader Joe’s, and sometimes from a nearby family farm. Their diet is augmented with organic vegetables from their own garden. M&S describe this family as "conscientious omnivores."

M&S trace Mary-Ann’s bacon to Niman Ranch, which sources its pork from pasture-raised pigs. The authors visit some of these farms to compare and contrast with Wayne’s concrete-floored buildings. While M&S come down squarely on the pro-pasturing side (no surprise there), I appreciated that they share what both Wayne and the Niman Ranchers have to say about each other’s practices, and what motivates their trade-offs. (Both castrate their male pigs, for example – boar meat simply won’t sell.) Wayne is proud to offer "the average citizen making the average wage a good healthy product." But an organic farmer retorts, "That guy thinks his food is cheap, but you and I are subsidizing that cheap food by paying for the social and ecological issues that are occurring in that community." The authors clearly agree.

M&S next discuss seafood, and share a surprising observation: the fish sticks Jake bought from Wal-Mart (made from wild-caught pollock) are much less ethically fraught than Mary-Ann’s farmed Atlantic salmon. Modern saltwater fish farms, it turns out, are also "factories" – large nets and cages lowered into the sea, packed to the gills with thousands of confined fish, and fed with ground-up "forage fish" harvested by commercial fleets. These farms emit unfiltered food waste and fish feces directly into the surrounding waters, and actually deplete wild fish stocks faster because they compete with them for food.

The last family Mason and Singer visit are JoAnn and Joe Farb, a well-off couple who live on 15 acres near the outskirts of the Kansas City metro area. They homeschool their children and stick to a vegan diet. In the chapters that follow, M&S argue against the claim that vegan diets aren’t nutritious enough to support healthy adults or growing children. They also make their strongest direct case to the reader for adopting a vegan lifestyle – which is too long to easily summarize here, although the SSC adversarial collab on meat eating covers most of the same points as M&S and reaches similar conclusions.

Tucked at the very end of this section is a short digression into dumpster diving and the practice of "freeganism": individuals who choose to glean what they need from the often profligate "waste" discarded by the rest of us. M&S seem to find this worldview fascinating, and I did too. The authors spend an evening scrounging up a surprisingly lavish dinner party with some of these urban foragers. When asked about their lives, the bohemians relay their mindset of "rejecting the priorities set by consumer society," like chasing status through the display of wealth and conspicuous consumption. M&S also note that freegans are "more flexible, in that they see no objection to eating animal products that have been thrown out. They want to avoid giving their money to those who exploit animals. [...] But their reasoning is impeccably consequentialist: If you oppose the abuse of animals, but enjoy eating meat, cheese, or eggs – just get it from a dumpster." The lesson M&S hope most consumers will draw, though, is to be mindful of the amount of food they waste, so the sacrifices that went into it won’t be in vain.

It’s clear that Mason and Singer want the reader’s ultimate takeaway to be "vote with your dollar," and the framework they chose is a great way to show how ordinary purchasing decisions are tied into the often dismal impacts of the food industry. I did find it hard to overlook the implicit class and tribal distinctions between the families they selected, which the authors largely gloss over. M&S make a very strong case that Wal-Mart et al. achieve their bargain prices by brutalizing animals, exploiting workers, polluting communities, poisoning the environment, and draining the taxpayer through government subsidies (not forgetting, say, the $8 billion stockpile of vaccines and antivirals the U.S. Senate funded when chicken-borne avian flu broke out in 2005). Still, a Wal-Mart shopper who’s inclined to believe that ‘ethical eating’ is a luxury practiced by snooty upper-crust people probably won’t see much to challenge their viewpoint. To me, this underscores the value of integrating more ethical food into the Standard American Diet – I suspect most of the Jakes and Lees in the world are way more likely to start buying Impossible Whoppers than they are to adopt the Farbs’ lifestyle.

So what should we eat?

Mason and Singer round out the book with specific recommendations about how to approach your shopping list. They start off on a dire note: "In supermarkets and ordinary grocery stores, you should assume that all food – unless specifically labeled otherwise – comes from the mainstream food industry and has not been produced in a manner that is humane, sustainable, or environmentally friendly. Don’t be fooled by terms like "all natural" or "farm fresh." They are often used to describe factory-farmed products."

Factory-farmed poultry: This includes >99% of all chicken and the vast majority of turkey. They’ve been bred to grow so fast that they can hardly stand and their organs can barely keep up when they reach their slaughter weight. The birds are crammed wingtip-to-wingtip in artificially-lit sheds. As the litter on the floor of the shed fills up with excrement it emits an eye-watering reek of ammonia and becomes a breeding ground for infection – not least because the ammonia causes rashes on the chickens' skin. The sheds pollute water resources and create health hazards for nearby communities. Poultry slaughterhouse jobs are dirty, dangerous, and low-paid.

Eggs from caged hens: As above, except battery hens are confined even closer together. These hens have their beaks stubbed short with a red-hot blade to prevent injuries when they peck each other. Their simulated day-night cycle is sped up to make them lay more eggs. After a year or so, they are "spent," and subsequently exterminated (usually via gas chamber). Their corpses are usually rendered into pet or animal feed, but sometimes they’re just dumped into a landfill. The natural lifespan of a hen would be five years or more.

Factory-farmed pork: Breeding sows are confined to crates so small they cannot turn around or walk. Pigs awaiting slaughter will spend their entire lives inside, on metal or concrete floors with no bedding. Their tails and often their teeth are clipped to prevent biting, but pastured pigs don’t bite each other in the first place. These factory farms use up 6 pounds of grain for every pound of boneless meat they produce, require large amounts of energy for climate control, and are responsible for literal giant cesspools that contaminate the surrounding countryside. M&S dryly sum up, "We don’t consider this an ethical food choice."

Veal: When the book was written, veal calves were infamously tied up and confined in tiny crates. These crates have since been phased out due to public outcry. The calves now have room to lie down, stand, and stretch, and may be placed with another calf for company, but their diet and movement are still heavily restricted. Their feed is essentially fortified milk, resulting in an iron deficiency that causes their characteristically pale pink-white flesh. Like factory pigs, they will never go outside. Ethically, modern veal is probably at least as flawed as factory pork, with a harsher carbon footprint on top of that.

Factory-farm dairy: Male dairy calves are "surplus;" if they don’t become veal, they can expect a similar fate to spent hens. Dairy cows are held in similar conditions to food pigs: usually an enclosed barn, sometimes a fenced-in patch of bare dirt, where they are fed a carefully prescribed ration of grains and nutritive supplements. Dairies are also a major source of pollution and greenhouse gases. So, M&S declare, "Intensively-produced dairy products should be avoided. Unfortunately, most of these problems occur in large-scale organic dairy production as well."

Feedlot beef: Beef cows are one of the few animals raised with the freedom to move and socialize with their herd. They spend 6-12 months grazing on pasture. Then, in the months leading up to slaughter, they’re moved to a feedlot with thousands of other cows and fed an unhealthy diet of corn and soy that causes gastrointestinal problems. Beef cattle are exposed to branding, de-horning, castration, and severe weather, but it’s still a better life than chickens and pigs get. Unfortunately, pound-for-pound, beef uses up much more water, petrochemicals, and land than other meats while producing tremendous amounts of poop and methane. (It’s more from burps than farts, for the record.)

Overall verdict on factory farms: M&S don’t mince words: "Supporting factory farming by knowingly buying its products is wrong." After re-iterating their support for vegan options, they suggest searching for sustainable and ethical meat products through resources like Eat Well Guide.

Farmed fish: "Fish farming is factory farming on the water," say the authors, with similar devastating impacts on the environment. Farming herbivorous fish like carp is better than farming carnivorous species like salmon, but the latter is more common on store shelves. M&S cite a study on rainbow trout that concludes fish perceive and respond purposefully to pain. Unfortunately, aquaculture as practiced is completely indifferent to their suffering.

Wild-caught fish: M&S suggest products labeled with "Fish Forever" (a certification of sustainability granted by the Marine Stewardship Council) or checking specific species against the database on Monterey Bay Aquarium’s Seafood Watch. They do caution, however, that fish is often mislabeled in stores. Still, if you’re going to eat vertebrates this is probably one of the most ethically sound ways to do it.

Shrimp: Most shrimp is farmed (see above) or wild-harvested by weighted trawling nets that chew up the seafloor and indiscriminately capture every sea creature in their path. M&S cite sources that claim this shrimp-to-bycatch ratio leans heavily toward bycatch – from 1:5 in the Gulf of Mexico to 1:14 or more in countries like Thailand (the largest single source of imported U.S. shrimp). The result is habitat loss, needless animal suffering, and depleted fisheries in developing nations. M&S say to avoid shrimp completely.

Lobster and crab: M&S claim that U.S. and Australian-sourced products (maybe Canada too?) are usually safer selections than those from Asian fisheries, most of which have little-to-no regulation or commitment to sustainability. Still, there are doubts about (e.g.) the future of Chesapeake Bay blue crabs under the pressure of commercial fishing. It is also uncertain how much crustaceans are able to suffer. The authors come down on the precautionary side, and recommend that crustaceans (and squid, and octopus) should be treated as if they do.

Bivalves: Dredging the sea floor for mollusks has the same ugly consequences as trawling for shrimp. However, bivalves like clams, oysters and mussels can also be farmed sustainably on suspended nets and cages in the water. M&S believe it is very unlikely that bivalves can suffer, so they have no ethical objection to eating sustainable shellfish of this kind. (In LW-adjacent circles, I more often see EAs draw the line at sessile bivalves, like oysters, which are fixed to one location. Motile bivalves like scallops can "flap" to swim and have rudimentary eyes, so a pain response might be adaptive in their case.)

Organic food: The authors are generally fans: "In most cases buying organic means less fertilizer runoff, fewer herbicides and pesticides in the environment, more birds and animals around the farm, better soil conservation, and in the long run, sustainable productivity." They do acknowledge that the touted health benefits of organic food could be better-substantiated, and that animals grown for organic meat may be only slightly better off than their industrial counterparts – but even a debeaked egg chicken in a packed organic henhouse is in much better shape and spirits than a battery hen. M&S think the extra cost for organic food is usually worth it, but they can’t blame you if you buy conventional produce instead and donate the savings to fight global poverty.

"Eat Local": All else being equal, the authors agree – but that’s rarely the case. Modern logistics chains are highly optimized; the energy costs and pollution of shipping food are minuscule next to those of growing it in the first place. It uses much less fuel to grow vegetables in a fertile country overseas and ship them to you than it does to grow them in a heated greenhouse next door. Also, many of the farmers in developing nations who grow our food are desperately poor, and have far more to gain from your custom than your first-world neighbors probably do. M&S remark that "buying local food, in season, is generally a good thing to do," but perhaps not always the best thing to do.

Fair Trade certification: The makers of Fair Trade-certified products are audited by an independent body to ensure they guarantee certain rights and wages to their workers. They must also avoid child labor (i.e., under age 15), prison labor, slavery, and debt bondage. Fair Trade is most often associated with goods like coffee, tea, chocolate, and bananas that are grown on tropical plantations; labor abuses are otherwise rampant on such farms, and M&S encourage you to buy Fair Trade goods whenever possible.

Obesity and over-eating: Yep, the authors go there. "Eating too much should be seen not only as a health problem, but also as an ethical issue, because it wastes limited resources, adds to pollution, and increases animal suffering." Citing a CDC report, M&S claim that weight-related health problems cost an extra ~$50 billion in private insurance bills and tax expenditures, which is ultimately distributed over every American adult. (Remember, these were 2006 numbers.) If everyone in the U.S. cut back to the same level of meat-eating as 1950s Americans, they argue, it would slash these costs and spare many animals from growing up on factory farms. How many? "By about the same amount as if 80 million Americans became vegans." M&S continue, "Some have eating disorders or metabolic problems that are difficult to control. But others just eat too much and should show some restraint. Along with the old-fashioned virtue of frugality, the idea that it is wrong to be a glutton is in urgent need of revival."

Nobody is Perfect, Everything is Commensurable: For all of their gloomy observations about the food industry and their incisive moral standards, I really appreciated that Mason and Singer ultimately approach their subjects and the reader in a measured, diplomatic way. As they wrap up the book, M&S acknowledge how paralyzing scrupulosity can be, and that achieving results matters more than rigorous personal purity: "You can be ethical without being fanatical." Without letting the reader off the hook, they accept that there’s a case for the occasional indulgence, or a rare exception due to circumstances. Even incremental progress makes a difference in the world, compared to wearied apathy or giving up in despair. In the end, we can all make better choices.