Does hypnosis really work for weight loss?

I am planning on going to a clinic in my area that specializes as in hypnosis to help me with weight loss. I am struggling with ability to lose weight. I skip out in my personal trainer and sneak junk food when I know I shouldn’t. I know I want to lose weight, but it’s not translating well with my bad habits. I wanted to get a professional opinion on the matter. Is hypnosis a common practice and does it really work?