Hey, Yodagirl, I can understand why you'd feel a little nervous. Pretty brave of you to join in! Well, if you can take it in a lighthearted way, that would probably be best. It might be just what you need in terms of motivation! And even if you don't "win," you will probably lose some weight while participating, and that's the real win!
As for the sabotage aspect, seems like on a daily basis the world offers sabotage to weight loss, in terms of the availability of certain foods, advertising, peer pressure, etc.--so in a way, that will be good training for reality!
So be of good cheer! Forge ahead! And remember you'll come out ahead no matter what.
"My religion is kindness." --His Holiness the Dalai Lama