TWO FAMILIES COMPETE FOR THEIR FUTURE HEALTH ON "20/20" AIRING JANUARY 7, ON ABC

Two overweight families face the challenge of a lifetime... With the help of Olympic gold medalist Paul Hamm and his twin brother and silver medalist Morgan, two families with real life problems are facing a real life extreme makeover. They have been warned that their health, even their lives, could be in danger if they don't get in shape. So they are getting an Olympic-style new diet, new lifestyle and new exercise regime that could change their lives forever. These two families are competing for their future health - but who will win? ABC News Correspondent Martin Bashir's report airs on "20/20," FRIDAY, JANUARY 7 (10:00-11:00 p.m., ET) on the ABC Television Network.

"20/20" is anchored by Elizabeth Vargas and John Stossel. David Sloan is the executive producer.