La Reid believes 'The X Factor USA' was the ''worst thing'' he has ever done.

The Epic Records chairman featured on the judging panel for the singing competition's first two seasons in 2011 and 2012 and has revealed he now regrets returning to the show for a second year.

Speaking at a Pepsi-sponsored Midem event in France, he said: ''It's the worst thing I've ever done ... The first season, yes, I had a great time.

''It was a little bit of a vacation. I'd been making music, working at running labels for a long time, and it was a little bit of, 'Let me just have some fun'.

''But the second season, I was fully engaged trying to run a label, and it wasn't fun anymore.''

The 59-year-old music mogul, who has worked with stars including Mariah Carey, Justin Bieber and Kanye West, continued to say the show ''almost destroyed'' his music taste because his expectations were lowered by the hopeful contestants.

He explained: ''It completely threw me off. What works for television isn't necessarily the thing that works in the traditional journey of music, so I adjusted my taste for television.

''But the truth is, I lowered my bar - my bar was quite high, if I'm being honest, and as a result I didn't have the same level of success. The bar is quite high again now, but it was damaging.

''I worked with Simon Cowell, who I love and have great respect for and he has great taste, but being around him for that long, I started to take on his taste, and I'm an amateur at having his taste - I'm good at my kind of taste.''