How this diet works:  

Jenny Craig started in 1983 by providing frozen meals to its clients as a means of food management. It has since branched out into cookbooks and programs that encourage clients to make food choices from readily available foods, as well as an at-home program for people who do not live close to an established center. Food is shipped to you by UPS, and personal consultations are conducted over the telephone. Personal weekly consultations for motivation and behavior change are a central part of the program. 

Good points:

Using frozen meals is convenient, and the meals are balanced and nutritious. There are many options to make the menu planning flexible and individualized. The individual weekly behavior consultations promote lifestyle changes and give on-going support. 

Bad points:

The Jenny Craig counselors are not highly trained health professionals. Jenny Craig relies on a food exchange system for menu planning, which many people find cumbersome and confusing. 

Duration: Indefinite 

More information about this diet:

You can not do this diet and eat at restaurants as you have to use their meals.   Alcohol is not okay, but you can have caffeine on a small scale - like one cup of coffee per day, etc.  You have to buy the meals.  It is doable if you are a vegetarian.

MANAGE YOUR CARBOHYDRATE INTAKE