I think a lot of people have a negative connotation of weight loss hypnosis, but in reality, it's something that studies have proven to be effective - check out this study. Together with a healthy diet, more substantial results are possible with the help of hypnosis for weight loss.
Hypnosis essentially brings you to a subconscious state where you are more willing to accept ideas or suggestions. You tend to become a better listener (girls, maybe you should try and hypnotize your guys, haha). A general misconception is that the patient is asleep or in a highly vegetative state when they are being hypnotized. It turns out the opposite is true - users are basically driven to a much more focused state where they zone out extraneous surroundings that may serve to distract them. It may seem simplistic, but think about how often you are distracted by the things that happen around you? I know I'm terrible with this - eventually I'm productive, but I can't do something for more than 15 or 20 minutes without taking a short break or diverting my attention.
It's really up to you to decide whether it's worth it to go this route - but again, it's a option that should at least be researched further if you are having trouble maintaining the motivation to lose weight.
Another option to take a look at is weight loss self hypnosis. Again, this may sound crazy but it's something that you can find a lot of information about on the web, or at your local book store. Seeing a true hypnotist may cost a decent amount of money, particularly in this economy, but take a few trips to the book store, grab a cup of coffee and do some reading. The coffee will only cost you a few bucks and you should at the very least get an idea of whether self hypnosis for weight loss is right for you.
One thing to note, that many people still don't understand, is that ANY weight loss program (including weight loss hypnosis) that advertises instant results will not work. Period. Real and lasting results never come without hard work, and it's good to be skeptical when trying out new options. If you are weary, you will ask questions, you will find answers and you will get to the bottom of the issue to filter out the good guys and the scammers.
People are always trying to make a quick buck on someone else's desperation, but if we would all use our minds a little more, we can avoid this!
Whether you want to exhaust all your options, are just curious, maybe a bit experimental, try out weight loss self hypnosis. It might be that added support or boost that pushes you one step closer to your weight loss goals.