Researchers asked 400 vegetarians, meat-eaters and ‘semi-vegetarians’ to record their feelings over a fortnight. Of the three groups, vegetarians experienced the most negative feelings and enjoyed social occasions least.

Lead author Dr John Nezlek, from the SWPS University of Social Sciences and Humanities in Poznan, Poland, said: ‘Sometimes unwittingly, and sometimes intentionally, vegetarians may be excluded from social events or made to feel odd or different because they are vegetarians. Such things tend to happen for members of social minorities.

‘Over time, such experiences can take their toll on a person’s wellbeing. We believe that this study is important because it is the first to show that defining one’s self as a vegetarian has implications for the quality of a person’s daily life.’