The Vegan Society says that more people are opting for vegan diet for seven or 30 days.
The temporary menu of people, who pledge to vegan, consists of animal-free products or by-products.
According to BBC, Vegan Society has found that there were 40 percent more people signing up to this temporary menu in the first two months of 2013 compared with the same period in 2012, reports femalefirst.co.uk.
Juliet Gellatley, director of the vegan and vegetarian group Viva, says most people do it either for health concerns or because they have developed greater awareness of animal rights.
"People might be prone to heart disease or want to get their cholesterol down. Or it might be because they've seen something on factory farming. But once people turn to veganism, they usually open their minds to the other issue too," said Gellatley.
"The third factor, which is more unusual, is environmental reasons such as global warning or deforestation," she added.