On the contrary, I see diets having a huge impact in sporting scenarios. Manipulated diets can assist athletes in achieving the best results. The idea of youthful athletes, however, evokes a number of other ethical debates.
Getting back to diet fads, the following video is a representation of common views towards diets and exercise, http://www.youtube.com/watch?v=1eA6CgzPJP4. A number of the more “comical” diet fads I have come across in my research include: The tapeworm diet (ingesting tapeworms to consume calories), the lemonade diet (only drinking lemonade for a period of time) & the amputation diet (loosing excess fluids to lose weight). These diets (and the image below) show the lengths people go to, to achieve a “healthy” appearance.