Where does fat really go when you lose it? The answer may surprise you!

When we lose fat, it must be eliminated somehow from the body. If you are like me, you just made some assumptions about how it gets flushed out. I actually never really gave it much thought and just kind of assumed it ends up being flushed down the toilet or when you sweat.

During a night of insomnia, I stumbled across this Ted Talk (link below) given by mathematician Ruben Meermen that explains the math behind weight loss and where the mass of the fat actually ends up.

Spoiler alert – I give away the answer in the text below. If you prefer to learn the result by watching the video (about 21 minutes) jump directly there and do not read below. Or save 21 minutes and jump to the punchline by reading the next three paragraphs.

I almost forgot about that video and then recently I started seeing this new fad being mentioned more and more online called “Cool-Sculpting”. This is a technique that is marketed as an effective way to help people lose fat. In some of the online postings about it, it mentions how fat is expelled from the body. I was quite disappointed to see that these articles were spreading false information about how fat is really expelled. These articles claimed that the fat is simply flushed out through your waste. This is just not accurate as demonstrated in the talk given by the gentlemen mentioned above.

Fat molecules are comprised of the three elements carbon, hydrogen and oxygen. Specifically, fat is c55h104o6 (55 carbon atoms, 104 hydrogen atoms and 6 oxygen atoms). According to Wikipedia 99% of the human body is made up of carbon, hydrogen, oxygen, nitrogen, calcium and phosphorous. The remaining small percent includes potassium, sulfur, sodium, chlorine and magnesium. All of these are necessary for life.

Anyway, back to fat. Fat is only those three molecules carbon, hydrogen and oxygen. So, when you lose, let’s say 10kg of fat, where does it go? Well some of it is flushed out as water, h2O. 16% to be exact. So out of 10kg of fat, only 1.6kg would be flushed out through waste, sweat, and tears. Surprisingly, at least to me it was, the other 84% is removed as carbon dioxide, co2, when you exhale. So that is 8.4kg of fat being expelled through your body as you breathe! Fascinating, isn’t it?

I encourage you to check out the 21-minute video to see the complete explanation and proof.

Concerning cool-sculpting, the idea behind this is that by freezing targeted areas of fat on your body, like love handles, the fat cells can be killed and then your body will dispose of them. The science behind cool-sculpting is that apparently fat cells die more easily at lower temperatures than your skin cells and other cells. So, the cool-sculpting equipment is set to freeze the fat at just the right temperature and without causing frostbite. Then once the fat cells are killed, it takes a few weeks for your body to eliminate them.

Anytime I read something and see that some details have been left out it makes me start to question the whole thing. I have not yet fact checked whether or not fat cells do indeed die more easily than skin and other cells at certain freezing temperatures but I would be surprised if it was false otherwise the cool-sculpting centers would not be spreading as quickly as they are. I even just came across one here in Switzerland. From what I have read, cool-sculpting does not work for everybody and it does not change the need to change your lifestyle and diet if you want to reduce fat. Or to be more precise reduce your c55h104o6. (If you called someone a c55h104o6-head do you think they would be insulted?)

The mathematics of weight loss by Ruben Meermen – TEDxQUT