The research on it is early, but it's thought to curve food cravings. However, its suggested you do acupuncture with a restricted calorie diet and exercise. So it's with a change in diet and lifestyle. It matters how skilled your acupuncturist is as well.
In my practice of health coaching we look into the psychology of eating, lifestyle factors, as well as genetics, which makes for a life lasting weight loss program, not just temporary weight loss :)