Vegetarianism

Humans are omnivorous, meaning they can survive on a variety of food sources and thrive on a broad diet that incorporates plant and animal matter including grains, fruits, vegetables, and meat. People who follow a vegetarian diet, in the simplest terms, do not eat meat. Vegan refers to persons and diets free of any products derived from animals. However, different cultures and individuals have distinct understandings of what constitutes vegetarianism. Because the definition of a term such as "meat" varies across cultures and regions, one person or culture might consider a diet that includes fish to be vegetarian while another person or culture does not.

People choose to become vegetarian for religious, philosophical, economic, environmental, or health-related reasons. While some religious groups and social reformers in the United States adopted vegetarianism in the nineteenth century, it was not until the 1970s that vegetarianism began to gain popularity among the general population. The percentage of Americans who say they are vegetarian has remained stable between 5 and 6 percent since the late 1990s, according to polling and analysis company Gallup. In 2019, 3 percent of US adults reported to Gallup they never ate meat such as beef, chicken, or pork; 7 percent reported they rarely ate meat; and 23 percent reported they occasionally ate meat. A survey conducted by researchers at Oklahoma State University in 2022 estimated as many as one in ten US adults are vegetarian or vegan. A poll commissioned by the nonprofit organization the Vegetarian Resource Group (VRG) found 6 percent of US adults were vegetarian in 2022, about half of whom were vegan.

Vegetarianism and veganism continue to influence the way Americans think about what they eat and have increasingly become part of the conversation surrounding what individuals and families can do to mitigate their carbon footprints. Data from the late 2010s and early 2020s suggest that more US adults are becoming part-time vegetarians. Many meat-eaters are reducing the amount of meat they consume, and restaurants increasingly offer vegetarian and vegan meals and menus. According to Gallup, in 2019 nearly one-quarter of US adults indicated having reduced their meat consumption in the previous year.

To most vegetarians, meat refers to the flesh of any animal. However, some consider meat to only mean the flesh of a mammal, which is commonly called red meat. People who consume fish and shellfish but no other meat may identify as pescatarians or pesco-vegetarians, while people who avoid red meat but consume poultry are known as pollotarians or pollo-vegetarians. People who primarily consume a vegetarian diet but occasionally consume meat may identify themselves as flexitarians.

Another division among vegetarians pertains to the consumption of other animal products such as dairy products and eggs. Vegetarians may consume dairy and eggs. Vegetarians who eat eggs are sometimes called ovo-vegetarians while those who eat dairy products are known as lacto-vegetarians. A vegetarian who consumes both eggs and dairy may be referred to as either a lacto-ovo-vegetarian or ovo-lacto-vegetarian. Vegans do not eat any animal-derived products, including eggs, milk, or dairy products (such as cheese and yogurt), and honey.

Within these established categories, however, there are many gray areas. For example, gelatin—a substance produced from the skin, bones, and tissues of animals—is found in food products as varied as vitamins, yogurt, and marshmallows. Many people who avoid meat or animal-derived products may consume gelatin, either knowingly or unknowingly. In addition, modern food processing often utilizes animal products in ways that may not be clear to consumers. In one example, McDonald's was sued for their french fry recipe. The suit came about because in 1990 McDonald's restaurants advertised their switch from using beef tallow in the oil for their fries to using pure vegetable oil because of health concerns about saturated fats and cholesterol. However, in 2001 it became widely known that McDonald's used "natural beef flavoring" on the fries. Several individuals sued McDonalds in at least five states, claiming that they had been misled into thinking the product was vegetarian.

In late 2022 the US Food and Drug Administration completed its first pre-market approval of the first food product made using cultured animal cells, referred to as lab-grown or cultured meat. Because they are made without killing an animal, eventual products made from lab-grown cells may be attractive to some vegetarians. However, vegetarians disagree over whether lab-grown meat could be permissible in a vegetarian diet. In a 2022 poll conducted by Veggly, a dating app for vegans and vegetarians, 28 percent of vegetarians reported they do not support and would not eat lab-grown meat, 50 percent reported they support but would not eat lab-grown meat, and 22 percent indicated they would eat lab-grown meat because it is cruelty-free.

Vegetarianism as a conscious lifestyle choice can be traced back to ancient India and ancient Greece. Some ancient populations likely engaged in vegetarian diets simply because meat was not available. However, the examples documented in ancient India and ancient Greece refer specifically to the avoidance of meat as a moral stand against violence toward animals. In India vegetarianism is closely tied to religious belief. Buddhism, Hinduism, and Jainism all originated in India and promote vegetarian diets. The term "vegetarian" first appeared in print in 1842 and became more widely used after the founding of the Vegetarian Society in England in 1847 as vegetarian ideas gained more adherents.

Many Europeans and Americans in the nineteenth century considered vegetarianism to be a fringe movement and associated it with radical ideas. However, vegetarianism became more widely accepted in the twentieth century. International cultural icons Mohandas Gandhi (1869–1948) and Albert Einstein (1879–1955) advocated the wide adoption of a vegetarian lifestyle. As the animal rights and environmentalist movements gained popularity and health concerns over meat consumption grew in the second half of the twentieth century, Americans reduced the amount of red meat they consumed.

Some scholars have also noted the role of cultural influences such as television and film in indirectly advancing these movements. Many books, movies, cartoons, and TV shows aimed at children depict animals as sympathetic creatures with human characteristics. This technique is a type of anthropomorphism, or the attribution of human traits to nonhuman beings or objects. According to one argument, people who hold a more sympathetic view of animals and attribute human feelings and thoughts to them are more likely to follow a vegetarian lifestyle or have misgivings about eating meat. Some observers refer to this phenomenon as the "Bambi Effect" in reference to the classic Disney film.

Many Americans become vegetarians because they believe a vegetarian diet is healthier than one that includes meat. The Physicians Committee for Responsible Medicine, the British Medical Association, and the World Health Organization (WHO) have published reports highlighting the health benefits of vegetarian diets. Findings include that vegetarians tend to weigh less, have lower cholesterol levels, and face a reduced risk of health problems including heart disease, high blood pressure, diabetes, and some kinds of cancer. While there is evidence a vegetarian diet may improve health, health care professionals and nutritionists warn that processed foods that are vegetarian or vegan may still contain high levels of sugar and saturated fat. Further, experts recommend vegetarians ensure their diet satisfies all of their nutritional needs. To meet nutritional recommendations, vegetarians may need to supplement their diet to compensate for deficiencies in protein, iron, calcium, vitamin D, vitamin B12, omega-3 fatty acids, and iodine.

As the global meat industry has been identified as a contributor to climate change, arguments emerged in the 2010s in favor of flexitarianism, vegetarianism, and veganism as ways to reduce individual and group carbon footprints. Food industry experts have noted a marked increase in new food products with "vegan," "plant based," and "no animal ingredients" labels, including meat alternatives sometimes called alt-proteins. For example, two plant-derived meat alternatives, Impossible Burger and Beyond Burger, became widely available to US consumers in fast-food restaurants and supermarkets in 2019.

Politicians and community leaders have begun to consider ways to reduce their city or state's meat consumption. For example, New York City, home to the largest school district in the United States, began citywide Meatless Mondays in its public schools in the 2019–2020 school year. In its 2020–2025 edition of Dietary Guidelines for Americans (DGA), the US Department of Agriculture included a healthy vegetarian dietary pattern alongside its healthy US-style and healthy Mediterranean-style dietary patterns for the first time.

Critics of vegetarianism have argued that meat is a necessary part of the human diet and that vegetarians are not as healthy as they claim. Some of these arguments focus on the difficulty in obtaining certain vitamins and important nutrients in a meat-free diet. For example, vegetarians are more likely than nonvegetarians to be deficient in vitamin B12, which may be connected to a higher risk of stroke. Vegans may be more likely to exhibit calcium deficiencies due to their avoidance of dairy products. Additionally, multiple studies have identified an association between vegetarianism and higher rates of depression, including one published in the Journal of Affective Disorders in 2023 that found depressive episodes were nearly twice as prevalent among people who do not eat meat than among people who do eat meat. Nutritionists and dietitians note, however, that such studies have had mixed results and a causal relationship between vegetarianism and mental illness has not been established.

Though nutrition experts endorse the benefits of vegetarian diets, vegetarians are sometimes still viewed negatively by nonvegetarians. In popular films and television, vegetarians have been depicted as being overly sensitive, preachy, and joyless or as weak, absentminded, and offbeat. Some studies have examined the relationship between meat consumption and masculinity, with one concluding the cultural linkage of meat and masculinity can discourage men from adopting a vegetarian diet. A study of an online vegan community published in the journal Discourse, Context & Media in 2022 found members actively challenging the assumed femininity of veganism and discussing the tendency of men to resist veganism because they think it will make them less masculine in the eyes of other men.

Nonvegetarians may also view vegetarianism as a threat to their lifestyle and fear that vegetarians are trying to force a plant-based diet onto them or restrict what they can eat. A 2019 study published in the journal Sustainability found that the perception of vegans and vegetarians as threatening was highest among men with lower levels of educational attainment. People who work in the cattle industry may also view vegetarianism as a threat to their livelihoods. Kansas ranks among the largest beef cattle producers in the United States. In 2022 the state passed a law requiring plant-based meat substitutes to include a "prominent and conspicuous" disclaimer if using the word "meat" on packaging.