This document defines vegetarians and vegans, provides demographic information on their numbers in the UK, and discusses reasons for adopting vegetarian or vegan diets. Some key points: - Vegetarians do not eat meat, while vegans also avoid other animal products like dairy and eggs. - Demographic surveys found the number of vegetarian children and adults in the UK rose between 2010-2012, though one report found the total number of vegetarians fell from 2001-2011. - More females than males follow a vegetarian diet, while more males than females are vegan according to one 2007 study. - Reasons for being vegetarian/vegan include ethics, health, religion and environmental concerns