KILLER “jihadi” Usman Khan was so vain about his appearance he paid for fat-busting cosmetic treatments days before his London Bridge rampage.
And while spouting support for IS and hatred for Western culture, he was known as Beyonce Boy in prison because of his love for the US pop superstar.
Last night campaigners said it showed the “empty and pathetic” ideology at the heart of Islamic terrorism.
Khan, 28, who also whined he had been bullied at school, ballooned to over 18st by gorging on fast food while living alone following his early release from prison.
The knife-wielding fanatic murdered Saskia Jones, 23, and Jack Merritt, 25, on Friday before being tackled by brave bystanders and then shot dead by police.
But even though he had been planning slaughter for months, he shelled out £1,000 for slimming treatments at a health clinic close to his terror lair in Stafford.
Sources said he had a series of £350 fat-freezing procedures which can reduce fat in the treated area by up to 35 per cent.