Vegan

The word vegan, pronounced /ˈviːgən/, or /ˈvɛdʒən/, was originally derived from "vegetarian" in 1944 when Elsie Shrigley and Donald Watson, frustrated that the term "vegetarianism" had come to include the eating of dairy products, founded the UK Vegan Society. They combined the first three and last two letters of vegetarian to form "vegan," which they saw as "the beginning and end of vegetarian.The British Vegan Society defines veganism in this way:
The word "veganism" denotes a philosophy and way of living which seeks to exclude — as far as is possible and practical — all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose; and by extension, promotes the development and use of animal-free alternatives for the benefit of humans, animals and the environment. In dietary terms it denotes the practice of dispensing with all products derived wholly or partly from animals.

Ovo vegetarians

Ovo vegetarians (or eggetarians) are vegetarians who eat eggs but not meat or dairy products. "Ovo" comes from the Latin word for egg. Pronunciation: /oe' voe/. A common health reason for choosing this diet is lactose intolerance.

This vegetarian diet excludes dairy products. Ethical reasons for doing this include constantly keeping a cow pregnant in order for her to lactate and the slaughter of unwanted male calves. Other concerns include the standard practice of separating the mother from her calf and denying the calf its natural source of milk. In contrast, however, hens are able to lay eggs for human consumption without being fertilized or reproducing. The common practice of keeping free range hens in the backyard illustrates this, and also demonstrates that hens can be treated as pets rather than egg-laying machines. This standpoint is in contrast to the ethical argument for lacto vegetarianism.

herbivore

lacto-ovo vegetarian

A lacto-ovo vegetarian is a vegetarian who does not eat beef, pork, poultry, fish, shellfish or animal flesh of any kind, but is willing to consume cheese, butter, yogurt and eggs. Lacto- means "milk" and ovo- means "egg".

In the Western world lacto-ovo vegetarians are the most common type of vegetarian. Generally speaking, when one uses the term vegetarian a lacto-ovo vegetarian is assumed. Lacto-ovo vegetarians are often well-catered to in restaurants and shops, especially in Europe and metropolitan cities in North America.

Some lacto-ovo vegetarians who are motivated by ethical reasons may avoid fertilized eggs as well as caviar, feeling that both involve the killing of beings or torture and exploitation of source animals. They avoid cheese that contains rennet and yogurts that contain gelatin as these two things involve killing.

In contrast, a vegetarian who consumes no animal products is called a vegan.

In the airline industry a lacto-ovo vegetarian meal is known by the acronym VLML.

Vegetarianism

Vegetarianism is the practice of a diet that excludes all animal flesh, including poultry, game, fish, shellfish or crustacea, and slaughter by-products. The reasons for choosing vegetarianism may be related to morality, religion, culture, ethics, aesthetics, environment, society, economy, politics, taste, or health.

There are several variants of the diet, some of which also exclude eggs and/or some products produced from animal labor such as dairy products and honey. Veganism, for example, excludes all animal products from diet. By some strict definitions, animal products are not used for attire either, whether or not the production of clothing or items has directly involved the actual death of an animal (dairy, eggs, honey, wool, silk, down feathers, etc.). A generic term for both vegetarianism and veganism, as well as for similar diets, is "Plant-based diets".

Properly planned vegetarian diets have been found to satisfy the nutritional needs for all stages of life, and large-scale studies have shown vegetarianism to increase longevity, improve health, and significantly lower risks of cancer and other diseases.