Alison Sweeney, Bob Harper, and Jillian Michaels

The Biggest Loser: Couples is back for Round 2, and this time it's bigger than ever. The seventh season, premiering Tuesday at 8pm EST, features the largest contestant to date, as well as both the youngest and oldest competitors ever to compete.  With 18-year-old Mikey at 385 pounds and Dan, who is 454 pounds at 19, trainer Bob Harper said the show will direct some attention at the youth weight problem in this country. "There's a young generation out there that really does need our help and we want to focus on teenagers in that way, in this season," he said.

While competing for a cash prize of $250,000 is a motivator, the 11 teams comprised of pairs with some relation to each other, are really fighting for their lives back. Executive Producer Mark Koops said that "Jerry and Estelle, the oldest couple we've had, [are] just incredible. Grandparents who are looking to get healthy for their grandkids as they've now retired." Both are 63.

And there may already be a fan favorite in the making. "We have a pair of Tongan cousins who everybody's going to fall in love with. In their community to be overweight is almost a badge of pride and they're trying to break a whole cultural myth that being overweight is good," Koops said.

Of course you can expect a little bit of drama, even between the contestants and the trainers. As Harper said, "One girl tested me more than I've ever been tested on the show. You're going to see me have a nervous breakdown on this girl. I watch [the episode] and it was like, 'Is that me? Did I do that? Was I yelling that much?' It was definitely a challenge let me tell you."