Lady Gaga has defended her South By South West Festival performance against bulimia claims after artist Millie Brown vomited on her during her rendition of 'Swine'.

The 27-year-old singer sparked outrage when performance artist Millie Brown vomited on her during her rendition of 'Swine' at the festival in Texas on Thursday night (13.03.14), but she insists the ''strange'' act is helping to change the art world.

During an hour-long keynote speech at the event, Gaga explained: ''Sometimes things that are really strange and feel really wrong can change the world.

''I'm not saying vomit is going to change the world. What I'm saying is it's the idea of a moment where it's truly just what we wanted to create and us just respecting each other as artists was enough for the performance to be worth it.''

Demi Lovato - who struggled with bulimia - had accused Gaga of ''glamorizing'' the eating disorder after Millie drank bottles of coloured milk before sticking her fingers down her throat and regurgitating onto the 'Applause' singer.

However Gaga brushed off the accusations, insisting she's a long-time fan of Millie's work and loves collaborating with her.

Gaga added: ''I've known Millie for I think like five years now and we've actually collaborated before, she was just in town and so we thought we would collaborate again.''