British pop star Tulisa Contostavlos has denied suggestions she has undergone cosmetic surgery, insisting her appearance has changed because her nose loses weight. The former N-Dubz singer has undergone a drastic makeover in recent weeks and her new look has sparked rumours she has gone under the knife, with many fans commenting on her noticeably slimmer nose, puffed-up lips and newly-defined facial contours. However, Contostavlos is adamant her new image is down to a drastic diet, which she claims has totally altered her features. She tells Britain's Daily Mirror, "I'm eight stone at the moment but my weight always fluctuates between eight and nine stone... But when I lose weight it goes from my face and everyone says my nose looks thinner. I swear on my life, I've not not had it done (surgery) - I've literally just lost weight and it goes from my nose."