nytimes: Its Poor Reputation Aside, Our Fat Is Doing Us a Favor, by Natalie Angier, 8/7/07

* Fat in the human body is "is dynamic and mercantile, exchanging chemical signals with the brain, bones, gonads and immune system, and with every energy manager on the body's long alimentary train." 

* "'We used to think of an adipose cell (fat cell) as an inert storage depot,' Dr. Barbara Kahn, chief of the endocrinology, diabetes and metabolism division at Beth Israel Deaconess Medical Center, at Harvard said. 'Now we appreciate that it is an endocrine organ,' in other words, an organ that like the thyroid or pancreas, secretes hormones to shape the behavior of other tissues far and wide. Squashed to the side a fat cell's cytoplasm may be, but it nevertheless spins out a steady supply of at least 20 different hormones. Key among them is leptin, an essential player in reproduction."

* "Fat also seems to know when it is getting out of hand, and it may resist new personal growth. Dr. Bruce M. Spiegelman (of the Dana-Farber Cancer Institute in Boston) and others have shown that with the onset of obesity — defined as 25 or more pounds above one's ideal weight — the fat tissue starts releasing potent inflammatory hormones. That response is complex and harmful in the long run. But in the short term, said Dr. Spiegelman, 'inflammation clearly has an anti-obesity effect, and it may be the body's attempt to restrain further accumulation of adipose tissue.'"