All Fat is Not Equal

Posted on February 3, 2010

Written by Bradford P Smith, Prof Emeritus
(Excerpted from the Harvard Health Publications online)

As you know, there are two types of fat cells. And it turns out that like cholesterol, there are the good guys and the bad guys!

White fat cells store most of our body fat, whether it is subcutaneous or visceral. Brown fat cells not only store fat, they also burn fat, so they are the good guys. Newborns have many brown fat cells to help regulate body temperature, and it was believed that they mostly disappeared as we grew up. But new research published in the New England J of Medicine shows that lean people with healthy metabolic indicators also have more brown fat cells found between their shoulder blades. Research is now examining how the number of these useful brown fat cells could be increased and activated.

Fat location is also proving to be important in humans. Fat stored subcutaneously in white fat cells is relatively inactive, while visceral abdominal white fat cells produce inflammatory factors and hormones. This information is increasing belief that waist size rather than body weight is the most important indicator of trouble, as waist size reflects the amount of visceral fat in a person.