Michelle Aguilar

It's all about families in the new edition of The Biggest Loser, which features four husband-and-wife teams and four parent-adult child teams trying to lose weight through diet and exercise as they compete for a grand prize of $250,000. Trainers Bob Harper and Jillian Michaels fly around the country, surprising their teams with the news they've been chosen for the show. Then it's off to The Biggest Loser ranch in California, where the contestants get a wake-up call from the show's doctor about what ages their bodies really are vs. their chronological ages because of obesity. Then the eight teams compete in their first challenge -- and the lucky winner gets immunity from this week's elimination. Alison Sweeney hosts the hit weight loss series.

This week, the contestants are left in the dark - literally - during a wild baked goods temptation, with the winner gaining considerable power that could completely change the competition. Later, host Alison Sweeney wakes the contestants up to gather them for the challenge, which will last from sun up to sundown - the longest challenge in Biggest Loser history. One contestant struggles with a decision about whether to stay at the ranch or go home, and then an elimination round sends another contestant packing. Trainers Bob Harper and Jillian Michaels also star.

In part two of this two-part episode, one group of contestants tries to convince their trainer that they are committed to stepping up their workouts. Later, one of the contestants has a heart-to-heart talk with her trainer about relationship issues with their family member. And a surprising weigh-in forces one team to send a family member home when they fall below the yellow line. Alison Sweeney is the host, and trainers Bob Harper and Jillian Michaels also star.

This week, trainers Bob and Jillian take their teams through very unusual workouts unlike anything they've done before. Later, Dr. Huizenga gives the contestants a very encouraging six-week progress report of how far they've come and how much healthier they are since coming to the ranch. Then the teams square off in a difficult balance beam challenge, with the winning team getting something very special from home. Alison Sweeney hosts.

In part one of this two-part episode, one team gets to go home and surprise their loved ones, while another team cashes in on a prize to spend 24 hours with their trainer for a day they’ll never forget! Then the contestants face their toughest challenge yet - a water tower competition that tests their endurance like never before. Later, one group of contestants incurs the wrath of their trainer when it seems they aren’t working out as hard as they need to, to stay on the ranch. Alison Sweeney is the host, and trainers Bob Harper and Jillian Michaels also star.

The contestants get to bid on the percentage of body weight they think theyll lose this week, and the highest bidding team can win $10,000 -- but only if they reach their weight loss goal. Then its off to a wild sprint and slide challenge, with the winning team earning a phone call home. Later, Chef Rocco DiSpirito drops by to teach the contestants how to shop for and make healthy, tasty and affordable meals before an elimination round sends another team packing. Alison Sweeney is the host, and trainers Bob Harper and Jillian Michaels also star.