'Biggest Loser' Keep-Fit Tips Revealed!

Fitness queen Jillian Michaels whips people into shape on "The Biggest Loser." Now Jillian is checking-in with former contestants to find out who kept the weight off, and how they did it!

Jillian Michaels and the

Former "Biggest Loser" champions Ali Vincent and Bill Germanakos also shared their best tips for keeping off the weight they lost.

Ali, who competed in season five, said, "A great way to stay on track is Biggest Loser Protein by Designer Whey -- it is the perfect way to supplement your daily diet. I make a shake in the morning to get my day started and use the 2GO paks in my water throughout the day."

Bill, the champ of season four, said, "You have to try to continue to make good decisions every day, as it's hard work to maintain your weight loss and a healthy lifestyle. A good tip to remember is that you should compensate for a bad day with TWO exceptionally good days, as it pertains to both diet and exercise... and NOT get down on yourself."