There have been multiple uses for hypnosis over the years, now including weight loss.  I’ve never really been hypnotized, I’ve tried, but it apparently takes more concentration than I have to offer.  In addition, you can apparently hypnotize yourself to improve sleeping patterns and reduce or eliminate insomnia.  But again, I apparently just don’t have the discipline for it. That being said, apparently they hypnotize you to try to help you to eat less, not actually crave fast foods, and otherwise take the healthy steps toward weight loss and get past your demons rather than allowing them to sabotage you over and over again. 

It is generally conducted by a qualified professional such as a therapist, and there have been some, especially when it is conducted at a young age, who have said that they experienced greater results and had no desire to overeat, to go after junk food, and otherwise to sabotage their own weight loss results in general.  This could be more of a placebo effect, you believe it will work, so you end up losing weight.  However, being that hypnosis has been used in so many capacities, it really wouldn’t be a far stretch to also use it for weight loss.