Why do we call it “burning fat”? It is a strange turn of phrase, as the body does not “burn” the adipose tissue (the technical name for “fat”). Of course, heat is involved in the base process of fat metabolism, hydrolysis, but the average person of course does not have this in mind. What the common phrasing captures is that the adipose tissue is now being used for fuel – burned up, as gasoline is burned up in a combustion engine as fuel for the vehicle. In this sense, the phrase “burning fat” captures something essential about the mechanisms of adipose metabolism. One mechanism of increasing this process overall is increasing the conversion of WAT (white adipose tissue) to BAT (brown adipose tissue) – known as the “browning” of fat.