One of the primary reasons people quit veganism is health concerns. While veganism can be a healthy and sustainable diet when done correctly. Some individuals may experience inadequate nutrition and deficiencies due to a lack of knowledge about plant-based sources of essential nutrients.

Preventing the exploitation of animals is not the only reason for becoming vegan, but for many it remains the key factor in their decision to go vegan and stay vegan. Having emotional attachments with animals may form part of that reason, while many believe that all sentient creatures have a right to life and freedom.

Vegans do not eat any animals or any food that is derived from animals. This means that vegans do not eat beef, pork, lamb, and other red meat. They also don't eat chicken, duck, and other poultry. And because fish are also living creatures, vegans don't eat fish or shellfish such as crabs, clams, and mussels.