CLA- Conjugated Linoleic Acid... 
Some scientist did a study on 180 fat people.  Half got this CLA, half got a placebo.  At the end of a year, the CLA group lost an average of 9% body fat, while gaining 2% muscle mass.  This without any change in diet, or exercise.  
Just started taking it, I'll let you know how it works out in a year 

.  Course, I exercise and diet to, but it can't hurt.