Jillian Michaels and Heidi Rhoades with their son Phoenix and daughter Lukensia on June 10, 2012 in Malibu, California. Credit: NPG.com

She's inspired legions of overweight Americans to shed unwanted pounds thanks to her work on NBC's The Biggest Loser, but tough-as-nails trainer Jillian Michaels has waged her own battle of the bulge since becoming a mom.

Bringing adopted daughter Lukensia, 2, home from Haiti less than a week after her partner Heidi Rhoades gave birth to their son Phoenix in May, Michaels tells the October issue of Redbook magazine that she found herself carrying around a few extra pounds after her family expanded.

"I went to interview Suze Orman for The Insider, and her wife said, 'You're chubby! And Suze said, 'You look like a mommy now,'" Michaels -- who just inked a deal to return as a trainer on The Biggest Loser for this winter's season 14 -- recalls of her friends. "I look at my body and I go: 'five pounds heavier.' But part of me really likes it."

As she and Rhoades raise their son and daughter, Michaels tells Redbook she looks to voluptuous celebrities like Beyonce rather than stick-thin models to inspire a healthy body image in her kids. "We talk about role models for her, like Beyonce, who has a more curvaceous figure," says the trainer, who also appreciates the bootylicious singer's hot bod. "My taste has changed. I prefer that look. For now, I want to look a little softer."

Deciding to return to The Biggest Loser after a two-season hiatus, Michaels will work with the show's first-ever kid participants, ages 13-17, in a bid to raise awareness of the growing childhood obesity epidemic. "Having recently become a mother of two, I am more passionate than ever about helping empower children and families with the information and resources they need to live a healthier life," she has said.