According to Now, the Black Eyed Peas singer put on 17lb for the part.
She said: "I actually gained 17lb. It was easy to put it on, it was fun and I loved it! I ate fried foods, everything, I just didn't work out at all. I didn't care, I didn't even think about it."
However, Fergie admitted that the weight wasn't as easy to lose after filming had ended.She added: "It was very hard to take off. It was the longest period of time I'd ever done that since I think high school.
"When I started working out again it was a big deal and it took me a while mentally to get back into that routine. So now I have a trainer which is great and keeps me motivated."
