there is a major difference, Jenny Craig has counselors, you have to buy their food, they are more expensive. I prefer WW because they have group meetings, you weigh in every week and have group sessions, they teach you how to change your eating habits. In order to stay within your desired body weight you need to change your life-style and WW teaches you how to do this, it is also available on line. WW also gives pointers on exercise, a whole new life-style, good luck