Now do not bet your entire years worth of grocery money, but bet a nice sum that is going to hurt if you'd lose...such as that mani//pedi, that monthly gym membership, that hair salon appointment, lunch out with loved ones, etc.
If you are addicted to gambling, do not do it. But, if you are not addicted, I think this is a perfectly safe opportunity to finally do something about your weight.
Good luck and leave a comment if you have any success! I would love to hear from you!