Entertainment Tonight ET Online ETOnline.com

Jillian Michaels said Tuesday that she's returning to The Biggest Loser and announced that the show's new season will include teenage contestants to highlight the problem of childhood obesity.

PICS: Celebrity Weight Wars: Better Skinny or Curvy?

Speaking during an appearance on the Today show, Michaels said she'd return to the NBC weight loss series that she launched along with trainer Bob Harper in 2004. The mother of two left the show in May 2011, saying she wanted to spend more time focusing on her children and charity activities. 

RELATED: Jillian Michaels Views Adoption as Her 'Calling'

"The show has chosen to take on something very controversial," Michaels told Today's Al Roker. "They're going to go after childhood obesity."

RELATED: Jillian Michaels Becomes Mother of Two

She said she just couldn't miss the opportunity to be part of the new season, which will put three teenagers on each team, although they won't be competing in the same way as the adult contestants. "For example, we won't be saying things to kids like, 'How much weight did you lose?' It's about getting them healthy, using words like 'healthy.'"

VIDEO: Jillian Michaels Uses Babies as Barbells

She added: "We won't be getting them on a scale -- it's about getting them on a softball team -- things like that. We're very cognizant of how touchy it is, how controversial it is."