Short answers, pulled from the story.
Humans have hunted and farmed animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates including chickens, sheep, goats, pigs, horses, and cattle, starting around 11,000 years ago. Goats, sheep, pigs, and cows were domesticated for food in the Near East and South Asia between 11,000 and 10,000 years ago.
The world produced 370 million tonnes of meat in 2023-60 percent more than in 2000. Three species accounted for nearly 90 percent of global production between 2000 and 2023: chicken, pig, and cattle. Chicken was the most produced at 34.2 percent of global production in 2023.
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. It classified red meat as probably carcinogenic to humans, in Group 2A. A 2021 review found an 11 to 51 percent increase in cancer risk per 100 grams per day of red meat.
Meat is mainly composed of water, protein, and fat. 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 proteins, myosin and actin, form the muscle's structure.
Meat production is by far the biggest user of land, accounting for nearly 40 percent of the global land surface. Meat, dairy, and egg production are responsible for 57 percent of greenhouse gases attributable to food production and 20 percent of all greenhouse gas emissions. In 2008, cattle farming was estimated responsible for 80 percent of Amazon deforestation.
In nutrition, red meat is meat from mammals, including beef, pork, lamb, mutton, veal, venison, and goat, and it does not necessarily appear red in color. White meat refers to poultry such as chicken and turkey, and some sources include fish while others exclude it. In culinary contexts, white meat often refers to certain cuts of poultry like the breast and wings, with legs and thighs called dark meat.