The `Born This Way` singer was suffering from food poisoning during a recent concert in London, causing her to vomit backstage, but she refused to throw up when performing in front of her fans because she didn`t want them to see she is as vulnerable as everyone else. She said: "The other night, in London, I had food poisoning. I was vomiting backstage during the changes. Nobody knew ... I just Jedi mind-tricked my body. I told myself, `You will not vomit onstage.` "I was also thinking, `If I do, they are going to think I`m drunk. And I don`t want them to think I am human, let alone drunk. I certainly wouldn`t want them to think I had something so ordinary as food poisoning." Despite the food poisoning incident, Gaga - real name Stefani Germanotta - says she considers herself to be a "great performer". She added in an interview with Vogue magazine: "Speaking purely from a musical standpoint, I think I am a great performer. I am a talented entertainer. I consider myself to have one of the greatest voices in the industry. I consider myself to be one of the greatest songwriters. I wouldn`t say that I am one of the greatest dancers, but I am really quite good at what I do. I think it`s OK to be confident in yourself."