The vomiting diet
The idea of vomiting after eating is an ancient Roman trick to stop the fat digesting into your system. Supermodels are also said to use this technique, also known as purging bulimia to much public disdain.
This diet is dangerous as you'd lose salts and fluid and the acid from the sick could damage your teeth and you could also tear your gullet. And you'd more than likely still be hungry after the ordeal.