12/30/2008 at 06:00 PM EST
Marty Wolff and his wife Amy met during the third season of NBC's The Biggest Loser
in 2007, got married in March 2008, and now are expecting their first child in July 2009, PEOPLE has learned exclusively.
Although they had been talking about having kids during their courtship, "After we got married, at a certain point, we let nature take its course," Amy says. "We are very excited!"
The Wolffs, who live in Omaha, Neb., run a weight loss and self-improvement program called Reality Wellness
. They also help organize local competitions, such as Shape Up Omaha, focused on getting folks fit.
"We take a token of what we learned on The Biggest Loser
and applied it," says Amy. "We've helped 250 people this past year lose 5,000 pounds!"
That is one of the reasons Amy, 29, and Marty, 28, keep a public profile. "We made a decision to stay in fitness to keep ourselves accountable," says Amy. "We are still comfortable where we are."
For Amy, who is three months along, that means being careful about her diet and exercise as she goes through her pregnancy. "So many friends have had to battle weight gain during pregnancy," she says. "They all have told me to watch out, it happens so quickly, and I'm like, 'I know!' I am cautious. I haven't gained any weight yet. I feel like the luckiest pregnant girl ever."
She is also very prepared. "One of the most exciting things was Marty's Christmas present for me," Amy says. "It was a box of everything maternity and right on top was a onesie that says 'I Love Mommy,' and I immediately cried when I saw it!"
As for how being on a reality show helped Amy get ready for the next few months, she tells PEOPLE, "Before going on The Biggest Loser
, I was a single career woman with no idea what my future would hold for me in two years. Having been on the show has prepared me for part of being pregnant."
The newest season of the show, Biggest Loser: Couples
, premieres Jan. 6 on NBC.