Meat

• 1. Introduction

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  Meat is animal tissue, mostly muscle, eaten as food, and three species alone supply nearly all of it. Between 2000 and 2023, chicken, pig, and cattle accounted for close to 90 percent of global production. In 2023, the world made 370 million tonnes of meat, 60 percent more than in 2000. Behind that single statistic sits a story that reaches back roughly 11,000 years, to the moment humans first kept animals rather than only hunting them. The word itself once meant something far broader. In Old English, mete simply meant food in general. How did a word for all food narrow to mean flesh? Why does eating it correlate with masculinity and lower openness to experience? And why do University of Oxford researchers call a vegan diet probably the single biggest way to reduce your impact on planet Earth? The answers run through biochemistry, philosophy, slaughterhouses, and the Amazon rainforest.

• 2. From The Hunt

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  Bison and deer fed the earliest hunter-gatherers, who depended on organized hunting of large animals. Paleontological evidence suggests meat made up a substantial proportion of the diet of the first humans. Horses and reindeer were among the large mammals hunted during the late Paleolithic in western Europe. The Neolithic changed everything by allowing animals to be domesticated and bred for systematic meat production. Goats, sheep, pigs, and cows were domesticated in the Near East and South Asia for food between 11,000 and 10,000 years ago. Chickens came later, around 7,000 years ago in East Asia, and the original purpose was cockfighting rather than eating. The horse was domesticated in Central Asia about 5,500 years ago, kept for draft work and riding. Once animals were under human control, breeders could begin shaping them toward the qualities producers and consumers wanted, a project that would eventually accelerate beyond anything early farmers could imagine.

• 3. The Factory Era

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  In 1966, the United States, the United Kingdom, and other industrialized nations began factory farming of beef cattle, dairy cattle, and domestic pigs. In the postwar period, governments had guaranteed farmers prices to push animal production higher. Output rose, but so did inputs: more animal feed, more veterinary medicines, more animal disease, and more environmental pollution. Intensive animal farming spread across the world in the later 20th century, replacing traditional stock rearing in country after country. In 1990 it accounted for 30 percent of world meat production, and by 2005 that share had climbed to 40 percent. Confinement brought visible costs to the animals themselves. Animals in these systems show abnormal behaviors such as tail-biting, cannibalism, and feather pecking. Procedures like beak trimming, castration, and ear notching drew questions of their own. Broiler chickens, bred to grow very large very fast, often develop leg deformities and become lame, and many die from the stress of handling and transport.

• 4. Engineering The Animal

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  In the 1980s, health concerns about saturated fats reshaped the British carcass. The fat content of United Kingdom beef, pork, and lamb fell from 20 to 26 percent down to 4 to 8 percent within a few decades, driven by selective breeding for leanness and changed butchery. Modern agriculture uses progeny testing to speed selective breeding and acquire desired qualities quickly. Heritability sets the limits of this work. Reproductive efficiency is only 2 to 10 percent heritable, while the muscle-to-fat ratio runs 40 to 60 percent. Some traits sit in recessive genes that breeders have struggled to exclude, including dwarfism and the doppelender or double muscling condition, which causes muscle hypertrophy and raises an animal's commercial value. Genetic engineering promises shorter programs by isolating genes for desired traits and reinserting them, so the genomes of many animals are being mapped. A recombinant bacterium has been developed to improve grass digestion in the rumen of cattle. Experimental reproductive cloning of sheep, pigs, and cattle has already succeeded, and asexual reproduction of animals with desirable traits is anticipated.

• 5. Inside The Tissue

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  Adult mammalian muscle is roughly 75 percent water, 19 percent protein, 2.5 percent intramuscular fat, 1.2 percent carbohydrates, and 2.3 percent other soluble substances. The two most abundant myofibrillar proteins, myosin and actin, form the muscle's structure and deliver power by consuming ATP. Several hundred sarcoplasmic proteins exist, and most are glycolytic enzymes that convert sugars into high-energy molecules. Connective tissue, made of collagen and elastin, makes up the remaining protein mass. Death starts a chemical clock. During the first day after death, glycolysis continues until lactic acid drives the pH down to about 5.5. Rigor mortis sets in within a few hours as ATP is used up, locking actin and myosin into rigid actomyosin and lowering the meat's water-holding capacity so it weeps. Meat cooked during rigor turns tough, but meat cooked just after death or after rigor resolves stays tender. Under hygienic conditions, meat can be stored just above its freezing point of minus 1.5 degrees Celsius for about six weeks, aging into greater tenderness and flavor.

• 6. Risk On The Plate

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  The International Agency for Research on Cancer classified processed meat as carcinogenic to humans, in Group 1, based on sufficient evidence that it causes colorectal cancer. The same agency, part of the World Health Organization, placed red meat in Group 2A, probably carcinogenic to humans. A 2021 review found an 11 to 51 percent increase in risk of multiple cancers per 100 grams per day of red meat, and an 8 to 72 percent increase per 50 grams per day of processed meat. The damage extends beyond cancer. A 2022 umbrella review tied each 100 grams of daily red meat to a 17 percent higher risk of type 2 diabetes, and each 50 grams of processed meat to a 37 percent higher risk. Heterocyclic amines and polycyclic aromatic hydrocarbons form when muscle meat is cooked at high temperatures, such as pan frying or grilling over an open flame, and both have proven mutagenic in laboratory experiments. Microwaving meat before finishing the cooking may cut heterocyclic amines significantly. A 2011 study found nearly half of US grocery meat and poultry contaminated with S. aureus, and more than half of those bacteria resistant to antibiotics.

• 7. The Planetary Cost

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  Meat production is by far the biggest user of land, accounting for nearly 40 percent of the global land surface. In 2008, cattle farming was estimated responsible for 80 percent of Amazon deforestation, through clearing forests to grow feed and to ranch cattle. Roughly 75 percent of deforested land worldwide is used for livestock pasture. Meat, dairy, and egg production cause 57 percent of the greenhouse gases attributable to food production, and 20 percent of all greenhouse gas emissions. Livestock now make up 60 percent of the biomass of all mammals on earth, ahead of humans at 36 percent and wild mammals at just 4 percent. A 2017 World Wildlife Fund study attributed 60 percent of global biodiversity loss to meat-based diets. The scientific calls for change have grown loud. In November 2017-15,364 world scientists signed a Warning to Humanity urging a drastic reduction in per capita meat consumption. A 2019 report in The Lancet recommended cutting global meat and sugar consumption by 50 percent, and a 2018 study in Nature said Western meat consumption needs to fall by up to 90 percent.

• 8. Meat And Meaning

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  Plato's Republic has Socrates describe the ideal state as vegetarian, a striking position from a founder of Western philosophy. Pythagoras believed humans and animals were equal and disapproved of eating meat, as did Plutarch, while Aristotle's Politics argued that animals exist to serve humans, including as food. Descartes wrote that animals were merely animated machines, but Rousseau countered that meat-eating is a social rather than a natural act, because children are not interested in meat. Religion draws its own lines. Jainism opposes eating meat, while some schools of Buddhism and Hinduism advocate vegetarianism without mandating it. The Quran forbids the meat of pigs, blood, and animals that die naturally as haram, against the halal that is allowed. Meat also carries gender. It is associated with men and masculinity, and research from African tribal societies to contemporary barbecue shows men are far more likely than women to prepare it. Claude Levi-Strauss suggested that roasting meat is more violent than boiling grains and vegetables. In modern societies men tend to eat more meat and prefer red meat, while women tend to prefer chicken and fish, a divide that meat marketers and meat-reduction advocates both study closely.