Now We Know Where Fat Goes When We Lose Weight

We breathe it out

Fat cells. Photo:

Losing weight involves losing fat. But as basic physics teaches us, matter never disappears. Contrary to popular belief, fat does not turn into muscle, and it doesn't get processed through our digestive system. So just where does that "burned" fat go? 

As new research reveals, we actually breathe it out. The Australian authors of a new paper—one of whom had recently dropped 33 pounds—arrived at this surprising finding by first examining the complex biochemical process involved in breaking down a single molecule of triglyceride, the most common type of fat that plagues humans, NPR writes.

Based on previous research, the researchers already knew that, along with energy, carbon dioxide and water are byproducts of fat metabolism. From there, they calculated that water accounts just 16 percent of burned fat, NPR continues. That means that a whopping 84 percent of that much-hated tissue is broken down into carbon dioxide. And where does that CO2 go? Out of your body as expelled breath.  

Unfortunately, as the BBC points out, simply hyperventilating in your chair after Christmas dinner won't make the cut for expelling all of those pesky triglycerides. 

Get the latest stories in your inbox every weekday.