BEYONCE's Super Bowl half-time show outfit had to be constantly taken in because the star lost so much weight while rehearsing for the main event.

The Single Ladies hitmaker wowed American football fans on Sunday (03Feb13) by reuniting with her Destiny's Child bandmates for an electrifying performance in a black leather bodysuit, complete with python and lace insets, created by Rubin Singer.

And the stylist admits he was always doing alterations to keep up with the 31 year old's ever-changing body.

He tells Entertainment Tonight, "When a performer is working so vigorously, they're shrinking constantly, and so she was losing weight every day. So we had to keep taking it in and taking it in and taking it in and doing tweaks and changes."

Meanwhile, Singer reveals it took about 14 people and 200 man hours to perfect Beyonce's look and create outfits for Kelly Rowland, Michelle Williams and her 120 backup dancers.