Biggest Loser Preview

"The Biggest Loser" returns to NBC tonight.

Four married couples and four parent-child teams will make up the competitors this season.

Trainers Jillian Michaels and Bob Harper say that makes their job harder.

"They're bringing in their baggage, they're bringing in their enabler," Harper explained.

As always, the contestants are competing for a new body, a healthier lifestyle and $250,000.