We willingly spend billions of dollars to win the war on body fat every year, and yet it always seems to come back, and more resilient than ever. Why is that? Why is that fat just keeps fighting back? Because as much as you think you want to lose fat, your body still isn’t convinced it should.

Benefits of FatThere are good reasons for your body to accumulate and store fat. Fat is a cushion of energy in times when we go too long without eating. It’s the safety net that keeps your heart, brain, and muscles going when we need more fuel than what’s immediately available.

But more than just a reserve of calories, fat plays a critical role in many body functions because it releases hormones. This discovery, in the 1990s, led fat to be reclassified as an endocrine organ. It turns out fat does some great things for us, though we don’t normally recognize them. What does fat do for us?

Enables Puberty — Ballerinas, who are often super skinny due to their strict lifestyle, will miss their periods or even delay puberty until after ending their career. This puzzled doctors and scientists until they found that fat makes both estrogen and leptin which are needed for puberty and reproduction.

Strengthens Our Bones — Fat isn’t just important for puberty, it’s also important for our bones. It turns out that body weight is a better predictor of bone mineral density, a measure of fracture risk, than age.

Boosts Our Brain Size — The health of our fat (yes, your fat can be sick or healthy!) affects our brain size. Patients with defective fat (fat that’s doesn’t make sufficient hormones) have smaller brains. Individuals with anorexia, who are characterized by having minimal fat, also see a decrease in brain size and volume. On the other hand, people with too much visceral fat are at risk of dementia. The health of our fat is directly connected to the health of our brain!

Enhances Our Immune System — On top of cushioning our most sensitive organs and keeping us warm, fat (through leptin) also strengthens our immune system and assists in wound healing. In fact, anorexics have weaker immune systems and heal more slowly than those with normal fat levels.

Helps us live longer — In times of sickness a little extra fat may prove beneficial. For instance, while fat has been blamed for heart attacks, strokes, diabetes, and a host of other serious illnesses, researchers are finding that low fat levels may make us even more vulnerable to death from those conditions. In many studies, being overweight actually lowers mortality from disease!

Without body fat, life as we know it wouldn’t exist. Perhaps fat is not quite the enemy we always make it out to be. At the very least, it is certainly more complex than the typical one-size-fits-all diet makes it out to be.