Is is possible? Definitely. Probable? Maybe. If I were to do my weight loss all over again, I'd do it a simpler way than how I've got it now, which is:
Pick someone I trust, who has more money than I do.
Get them to sign an agreement that they get money from you, and don't pay it back until you reach goal weight or turn 65.
Give them a lot of money
Set up an automatic payment into their account equal to the cost of 2 weight watchers meetings a week
Initially, you may actually put on weight, but as time goes on, you'll start to think of all of that lovely money, just sitting there, losing value due to inflation. This method is probably not the fastest, but I'm sure it would work. I am 11 years since I was at goal. You do the maths and work out how much incentive there would be to lose weight from all that money.
Similarly, I suggested to my brother that he and I have a system where we each give each other $10,000 when the other person reaches goal. However, he's pretty much given up on reaching goal, so I don't think his heart is in it, but if it was, I'm sure we'd both reach goal.