The Truth About Fat

The perception about fat is that it is a foreign substance that attaches to our hips, thighs and belly. It’s really not part of us like our arms and legs. It’s something that we try to lose. In reality, our fat is part of our functioning system. Fat cells play a vital role in our survival, secreting hormones and interacting with other organs. Fat cells, in fact, function as an organ.

It used to be thought that our fat cells only got bigger rather than increasing in number. That we were born with a specific number and that number stayed the same. It’s now thought that fat cells can increase in number quite easily. “There’s only room for about 1.2 micrograms of fat per cell,” according to Samuel Klein of Washington University. After that, the body has to go looking to build out a new room in the storehouse. And once you’ve constructed a new addition for your fat cells they will be around for a long time. Going on a diet may reduce their size, but not their number. The body is not going to dismantle that new room unless it is has been left unused for quite a while. “The half life of a fat cell is probably at least a year, but I think it’s longer,” says Philip Scherer a cell biologist at the Albert Einstein School of Medicine.

The fat organ is a specialized machine whose job it is to keep its cells full of fat. The beauty of fat digestion and absorption in humans is that ingested fat does not go first to the liver for processing like the rest of the meal. It goes directly into circulation where it can be picked up by fat cells and stored away. Fat cells secrete an enzyme called lipoprotein lipase so they can lasso passing lipoproteins (the primary form of circulating fat) and suck in the fat. It really is as the saying goes “straight from the lips to the hips.”

The fat organ also exerts control on the appetite. It used to be thought that fat cells were passive storehouses for excess energy. In 1994 it was discovered that fat actually produces and secretes hormones. Hormones are the chemical messengers the body’s various systems use to communicate with each other. Discovering the hormone, leptin, was like discovering that cats and dogs talk to each other when we’re not around. The question that follows is: what the heck are they talking about? Fat cells, it turns out, are telling the appetite control center of the brain when they are full and when they are not. When fat cells begin to empty there is less circulating leptin, resulting in an increase in appetite. When fat cells are full there is more leptin and a lower appetite. Obviously, the body is trying to control eating based on how much energy is in the storehouse. Leptin, unfortunately, has not proven effective as an appetite suppressant in pill form or even when injected. Scientists still don’t have all the answers to this puzzle.

The fat organ also secretes a hormone called adiponectin. This hormone assists insulin in its job of helping sugar get into cells where is it is used as fuel or stored. “The more fat you have, the less adiponectin your fat cells produce,” says Scherer. Almost as if the body figures it already has enough stored energy and doesn’t need anymore. Those with low levels of adiponectin exhibit insulin insensitivity. Insulin insensitivity is a hallmark of type 2 diabetes and syndrome X (also known as metabolic syndrome and insulin resistance syndrome).

Where does this discussion leave us? Hopefully with a little more compassion for our fat. It is, after all, part of us, just like our livers. It’s part of us and probably will be for a long time. It may get slightly smaller and larger form time to time, but unless it gets smaller for a consistently long period of time, it probably won’t go away. To remodel our structures we have to live into them. In other words, live today as if your body was that remodeled structure. Live that way consistently enough and your body will reconstruct itself. But use that old room even for holiday guests and your body will want to keep it around till next year.