Vegetarianism
Some people who call themselves vegetarians and eat fish or sea food are not vegetarians, because fish and sea creatures are also animals. Such people are sometimes called pescetarians. There are also many people who are not vegetarians, but do not eat too much animal food. Some eat only very little meat (so-called "flexitarians" or "semi-vegetarians"), some eat only fowl ("pollotarians"). There is also a philosophy called freeganism, it means eating animal products only if  otherwise they will be thrown away to waste - such as food thrown away by restaurants.