WE’RE BORN with brown fat and newborns have, relatively speaking, quite a bit of brown fat between the shoulder blades.
Until 15 or 20 years ago, brown fat was thought to be insignificant in adults. It was also believed that the tissue disappeared as a person got older, until the 1970s when it was discovered during PET/CT scanning of adults. The largest deposits detected were around the neck (collarbone) and along the spine, while smaller deposits were noticed around the heart and kidneys.
The amount of brown fat in adults is difficult to determine, but it is estimated to be 200-1,500 grams (7-53 ounces), while some adults have none left or never had any in the first place.
