Vegans don’t eat meat because they view it as inseparable from animal suffering, environmental destruction, or both. While some people drop meat purely for health reasons, veganism as a philosophy goes further: it rejects the use of animals for food, clothing, entertainment, or any other purpose. The reasons break down into three main categories, and most vegans are motivated by some combination of all three.
The Ethical Argument Against Eating Animals
The most common reason vegans give for avoiding meat is a belief that killing animals for food is morally wrong when alternatives exist. This position rests on a simple observation: animals are sentient. They feel pain, experience fear, and have an interest in staying alive. The scientific evidence for sentience is considered extremely strong for all vertebrates, which includes every animal commonly raised for meat.
The philosopher Peter Singer framed this idea through the concept of “speciesism,” which he defined as a prejudice or bias in favor of the interests of one’s own species over others. Singer argued that if two beings can suffer equally, giving less moral weight to one simply because it belongs to a different species is no more justified than discrimination based on race or sex. The core question he posed: “Can they suffer? Can they enjoy life? If so, they have interests that we should take into account.”
For vegans, this logic leads to an uncomfortable conclusion about modern farming. Roughly 75 billion broiler chickens, 7.8 billion laying hens, and 1.5 billion pigs are farmed each year globally. Many of these animals spend their lives in physically and behaviorally restrictive intensive systems. Standard practices across the industry include separating dairy calves from their mothers, castration without pain relief, tail docking, and debudding (removing horn tissue from young cattle). Vegans look at these realities and conclude that participating in this system, even indirectly through purchasing meat, is something they’re not willing to do.
The Environmental Cost of Meat Production
Environmental concerns are the second major driver. Producing meat generates far more greenhouse gas emissions than growing plants, and the gap is enormous. One kilogram of beef produces between 14 and 68 kg of CO₂ equivalent, depending on the farming system. Pork generates 4 to 12 kg, and chicken 1.4 to 3.3 kg. Legumes like beans and lentils, by contrast, average around 0.27 kg of CO₂ equivalent per kilogram in the United States. That means beef can produce more than 100 times the emissions of the beans that could replace it on your plate.
Water use follows a similar pattern. Producing one pound of vegetables requires about 42.5 gallons of water. One pound of chicken requires roughly 571 gallons, about 13 times more. Beef is even more water-intensive. For vegans motivated by climate change and resource conservation, these numbers make the case on their own: eating plants directly, rather than feeding plants to animals and then eating the animals, is a vastly more efficient use of the planet’s resources.
Health Reasons for Skipping Meat
Some people arrive at veganism through health concerns rather than ethics. Data from the EPIC-Oxford study, one of the largest long-term dietary studies in Europe, found that vegans had a 47% lower risk of type 2 diabetes compared to meat eaters, though much of that difference was explained by vegans tending to have lower body weight. Vegans in the study also had lower blood pressure, with systolic readings averaging 2 to 4 points lower than meat eaters even after accounting for weight differences.
Heart disease risk was about 18% lower in vegans than in meat eaters in the same study, though the relatively small number of vegans in the group meant that finding wasn’t statistically conclusive. These aren’t magic-bullet numbers, and a poorly planned vegan diet won’t automatically protect you from anything. But the general pattern across nutrition research is consistent: diets built around whole plant foods are associated with lower rates of several chronic diseases.
Antibiotic Resistance and Food Safety
A less well-known concern ties meat production to a growing public health crisis: antibiotic resistance. Intensive animal farming relies heavily on antibiotics, not just to treat sick animals but to prevent disease in crowded conditions and, in some countries, to promote faster growth. Chickens receive an average of 148 mg of antibiotics per kilogram of body weight produced each year. Pigs receive 172 mg/kg. This routine use creates breeding grounds for antibiotic-resistant bacteria, which can then reach humans through the food chain or through animal waste entering the environment.
These resistant bacteria can cause infections that are harder to treat, last longer, and sometimes prove fatal. For some vegans, avoiding meat is partly about refusing to support an industry that contributes to a problem the World Health Organization has identified as one of the top global threats to human health.
What Vegans Eat Instead
Vegans build their diets around vegetables, fruits, grains, legumes (beans, lentils, chickpeas), nuts, seeds, and products made from these ingredients like tofu, tempeh, and plant-based milks. The one nutrient that genuinely cannot come from plants is vitamin B12. This compound is made by bacteria and accumulates in animal tissue through the food chain. Plants neither need nor produce it, so unfortified plant foods contain none.
This makes B12 supplementation non-negotiable for vegans. Research suggests a daily intake of approximately 6 micrograms optimizes all markers of B12 status, though recommendations vary by country, from 1.5 micrograms per day in the UK to 4 micrograms in the EU. Many nutrition researchers suggest 4 to 20 micrograms daily as a practical range to prevent deficiency across all life stages. Fortified foods like nutritional yeast, plant milks, and breakfast cereals can contribute, but most vegans rely on a supplement to be safe.
Other nutrients that require some attention on a vegan diet include iron, omega-3 fatty acids, calcium, and zinc. All of these are available from plant sources, but you need to be intentional about including them regularly. A vegan diet that leans too heavily on processed convenience foods and refined grains can easily fall short, just as any restrictive diet can.
It’s Rarely Just One Reason
Most vegans don’t point to a single motivation. Someone who initially drops meat for ethical reasons often becomes more aware of the environmental data over time. Someone drawn in by health benefits may find the ethical arguments increasingly compelling once they start paying attention to how animals are raised. The Vegan Society, which coined the term in 1944, defines veganism as seeking “an end to the use of animals by man for food, commodities, work, hunting, vivisection, and by all other uses involving exploitation of animal life.” That’s a broad principle, and people arrive at it from many different starting points. What they share is the conclusion that the costs of eating meat, to animals, to the planet, or to their own health, outweigh the reasons to continue.