Here's the rule. No one over 12 should believe advertisements, especially when they provide miracle cures. The diet product, hoodia, makes the point.
A UK company has been told to amend advertising for a hoodia gordonia product. Why?
Because they claimed that it could cause you to reduce calorie intake, lose weight, boost mood, and even act as an aphrodisiac ... slim AND sexy!!
And while they listing its unbelievable accomplishments, they also claimed that Oprah Winfrey (and the stars of Desperate Housewives, no less) had used or recommended hoodia.
These claims were refuted by a UK advertising standards agency, along with their claim that they had a case study supported by scientific evidence.
You can read more in this brief note in Food Navigator, which also provides great supporting articles on the Hoodia diet product itself. Interestingly, expect this site to give you a very pro-industry point of view.