A semi-vegetarian diet (SVD), also called a flexitarian diet, is one that is plant-based or with the occasional inclusion of meat. In 2003, the American Dialect Society voted flexitarian as the year's most useful word. Flexitarian is a portmanteau of the words flexible and vegetarian, signifying its followers' less strict diet pattern when compared to other vegetarian pattern diets.
Vegetarianism is the strict practice of abstaining from consuming meat. Flexitarianism is a neoteric term that gained a considerable increase in usage in both science and public sectors in the 2010s. Flexitarian was listed in the mainstream Merriam-Webster's Collegiate Dictionary in 2012. Other neologisms used as synonyms for semi-vegetarianism are demi-vegetarianism and reducetarianism.
Common reasons for adopting a semi-vegetarian diet include religious restrictions, weight management, health consciousness, issues relating to animal welfare or animal rights (see ethical omnivorism), the environment (see environmental vegetarianism), or reducing resource use (see economic vegetarianism). Flexitarians may have attitudes and endorsement behavior concerning health issues, humanitarianism, and animal welfare.
The main fundamental of some specific semi-vegetarian diets is about the inflexible adherence to a diet that omits multiple classes and types of animals from the diet in entirety, rather than a sole focus on reduction in consumption frequency. Some examples include:
- Macrobiotic diet: a plant-based diet and it may include occasional fish or other seafood. Though some advocates of the macrobiotic diet promote a vegetarian (or nearly vegan) approach as the ideal. 
- Pescetarian diet: someone who follows this diet eats fish and/or shellfish and may or may not consume dairy and eggs. The consumption of meat, such as poultry, mammal meat and the flesh of any other animal is abstained from. In the past, some vegetarian societies used to consider it to simply be a less-strict type of vegetarianism. This is no longer the case now that modern day vegetarian societies object to the consumption of all fish and shellfish.
- Pollotarian diet: someone who follows this diet eats chicken and/or other poultry and usually eggs as well. A pollotarian would not consume seafood, the meat from mammals, or other animals often for environmental, health or food justice reasons. This term is the most recently coined term for a semi-vegetarian diet pattern; it’s not particularly as well established and accepted in the English lexicon. The structure of the word pollotarian may have been inspired by the well known term pescetarian in that it is a portmanteau of a word borrowed from Italian, possibly pollame, and the English word vegetarian.
All semi-vegetarians could accurately be described as people who eat a plant-based diet, but there is no firm consensus how infrequently someone would have to eat meat and fish for their diet to be considered a semi-vegetarian diet rather than a regular plant-based diet. The average American consumed an estimated 222 pounds (101 kg) of meat in 2018, so comparatively a semi-vegetarian would have to eat much less. Once someone is able to consistently forgo meat for 5+ days a week, they can be considered a flexitarian.
Recurring conditions of a semi-vegetarian include consuming red meat or poultry only once a week. One study defined semi-vegetarians as consuming meat or fish three days a week. Semi-vegetarianism may be the default diet for much of the world, where meals based on plant materials provide the bulk of people's regular energy intake. One estimate is that 14% of the global population is flexitarian.
Society and culture
In the United Kingdom, there was increased demand for vegan products in 2018. A 2018 study estimated that the amount of UK consumers following a “meat-free diet” had increased to 12%, including 6% vegetarians, 4% pescetarians and 2% vegans. A 2018 poll indicated that 10% of adult Canadians considered themselves as vegetarians or vegans, among whom 42% were young adults. A high estimate for meat consumption per person in 2007 was 301 pounds (137 kg) (for Luxembourg), including consumption of beef, pork, turkey, and chicken. In 2019, an international group stated that the adoption of the flexitarian diet would "save lives, feed 10 billion people and all without causing catastrophic damage to the planet," when compared to the current western diet.
- Dawn Jackson Blatner (author of The Flexitarian Diet)
- Entomophagy, consuming insects, which is another environmental approach for obtaining food
- Ethical eating
- Ethical omnivorism
- Ethics of eating meat
- Food and drink prohibitions
- Meatless Monday
- Meat tax
- Reducetarian Foundation
- Sustainable diet
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There are many forms of vegetarian diet from the semi-vegetarian (consumes meat infrequently)...
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semi-vegetarian: mostly follows a vegetarian diet but eats meat, poultry and fish occasionally
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