i heard a commercial on the radio for some product that supposedly gets rid of the "hard to burn brown fat". does such a thing really exist?

Brown fat (brown adipose tissue) is metabolic fat that produces heat, and makes up only one percent of an adult's body weight. In human newborns, it comprises up to 5% of the body weight, but diminishes with age.

It is important in small mammals living in cold environments and in animals that hibernate. as brown fat contain a large number of mitochondria that immediately oxidize fatty acids. This produces a large amount of heat, which allows animals awakening from hibernation to warm up quickly.

Studies are still being conducted n the effect of brown fat and obesity. The Medical School at Chicago University, Duke University, and Colorado State, to name only a few, are conducting studies on this. Other sources say that obesity ciould be related to defective brown adipose tissue.

Just for reference, I went to Google,typing in "brown fat" as the exact phrase in the advanced search. Google returned over 5,000 hits on the subject-matter.