Jessica Simpson is piling on the pounds while promoting her new country album, because the self-confessed "nervous eater" is terrified about her tour.

When the sexy star appeared on U.S. morning TV show Good Morning America last week sporting a heaving bosom and wearing loose-fitting clothes, gossips started speculating she is pregnant with American footballer boyfriend Tony Romo's child.

But Simpson, 28, insists her fear of failure is responsible for her new healthier look.

She tells the National Enquirer, "I'm a nervous eater and this tour has made me a nervous wreck."