Obviously, when you are sweating like mad from working out, fat is pouring off of you right? Nope! It’s a common misconception that we burn and melt fat off our bodies, getting rid of it via sweat or trips to the bathroom. But low and behold, that is wrong, wrong, wrong. It’s a wee bit more complicated yet wildly fantastic that most of the fat we “lose” we are breathing out into the atmosphere.
How so you ask? After reading this article (R. Meerman, A. J. Brown. When somebody loses weight, where does the fat go? BMJ, 2014; 349 (dec16 13): g7257 DOI: 10.1136/bmj.g7257), I asked a very smart, scientifically trained medical provider (Allen Chapman PA-C) if this was a bunch of malarkey, and here is his response…and I took the liberty to paraphrase:
When fat is metabolized it generates energy which has no weight. This energy is mostly in the form of heat, water and carbon which our bodies get rid of by binding it with oxygen which forms a gas, which we exhale. So since the weight of the carbon is higher than the weight of the water, it is technically true that most of the mass is lost via breathing.
What is fantastic is that once we exhale this “fat”, plant life (remember photosynthesis) readily absorbs it and we get green trees and are in effect feeding the forest. Weird to think about but actually very awesome. Thankfully the opposite doesn’t occur. You can’t breathe in carbon dioxide and convert it to fat. So take heart and be happy – that extra exhaling you do going up the stairs, or walking fast or skiing or whatever makes you breathe a little harder – is good for you and good for mother earth!
(R. Meerman, A. J. Brown. When somebody loses weight, where does the fat go? BMJ, 2014; 349 (dec16 13): g7257 DOI: 10.1136/bmj.g7257)