The Ecology of Humans (39) The Fat System

The Fat System

Fat is more than the body’s energy storehouse. Fat is a major player in a body’s functioning, acting as an endocrine organ. Fat cells continuously dispatch dozens of potent chemical signals to myriad tissues throughout the body, including the brain, muscles, liver, reproductive organs, and immune system.

Fat orchestrates a range of bodily activities. Fat tells the brain how much energy the body has. Fat influences blood clotting and blood vessels constriction. Fat kibitzes on reproduction, playing a role in synthesizing sex hormones such as estrogen, and signaling whether conditions are favorable for pregnancy.

Fat unleashes or suppresses the immune system. The immune system and fat have an intertwined relationship because the body needs energy to fight infection. The intimate relationship with the immune system explains why excess fat triggers stress responses and systemic inflammation.