As a lover of all things psychological, I am drawn to this show, but be warned that it is for adults and mature teens only, for several reasons. The fact that the people featured literally live on one food is not a positive message for children, particularly since those foods are often junk, like French fries, pizza, or burgers.
Some featured guests have tragic stories as to how and why they have become addicted to this one food. Vomiting and other ill effects can be shown, and the show's hosts, particularly nutritionist J.J. Virgen, are not above using scare tactics to get guests to change their habits. These can include graves with the guests' names on them or big coffins filled with what the guests will never get to do or see if they do not stop eating this food. My concern is that children would either take this show as a license to be overly picky, or become frightened that they will die horrible deaths if they ever touch a candy bar again.
Besides that, the show sends the message that such entrenched eating disorders as the guests have can be "fixed" in a short time. This is not only untrue, but paints an unrealistic and possibly dangerous picture of eating disorders of any kind. Only watch if you're an adult and a discerning foodie.