Where Does All the Fat Go?

We’ve all heard the phrases “fat-burning,” or “burning calories.”

A good workout will do both.

The other night I had the privilege of visiting the newly-renovated State Capitol 24 Hour Fitness in downtown Sacramento, and I was struck by how many people were working out in this spacious new facility. At least a hundred people. Huffing and puffing. Pounding the treadmills. Working the stairmasters.

Maybe I’m weird, but – as I looked out among the crowd from my perch atop the goliath stair-stepping machine – I could almost picture tiny thought bubbles above each of their heads: “320 calories burned” and so forth.

As I thought about it further, a curious yet disgusting question entered my mind: Where does all the fat go?

It has to go somewhere, right? So I wondered, does it propel into the atmosphere around us, in some vapor-like force? Or does it melt inside of our bodies like some sort of liquid, alien-like plasma? Both theories thoroughly disgusted me.

So, I did a little research. And I thought I’d pass on the answer to you, in case your brain is as curious and peculiar as mine.

According to the Mayo Clinic's registered dietician Katherine Zeratasky, body fat breaks down in a series of complex metabolic processes.  When you “burn” fat, resulting waste products of that metabolic fire get expelled through sweat, urine, and carbon dioxide that gets exhaled from your lungs.

So, I was half right. The fat does enter the atmosphere around us at the gym. Your lungs serve as a “chimney” of sorts that expel the fat by-product into the air. And the internal metabolic “burn” is exactly that: a process that occurs inside, among the body’s 10 to 30 billion fat cells. Physical activity stirs up friction like two sticks rubbing together to create a fire, and the result is your fat literally getting burned into oblivion.

This all gives new meaning to the phrase “Let’s get fired up!”  Here's to your next inferno.