Yusuf Islam, formerly known by his stage name Cat Stevens (born Steven Demetre Georgiou on 21 July 1948 in London, UK), is an English musician, singer-songwriter, multi-instrumentalist, educator, philanthropist and prominent convert to Islam.

from wikipedia: . . .

in early 1968 at the age of 19, he became very ill with tuberculosis. During several months in the hospital and a year of convalescence, Stevens began to question aspects of his life, took up meditation, read about other religions and became a vegetarian.

He apparently continued to be vegetarian throughout his time as a highly successful recording artist.

. . .He formally converted to the Islamic faith in 1977 and took the name Yusuf Islam in 1978 . . . Following his conversion, Yusuf Islam abandoned his career as a pop star.

At present it is not clear whether he also abandonded his vegetarianism. A Muslim Vegetarian Society was founded in London in 1995, but we are unaware of any connection with Yusuf Islam.