In 2013 I posted this (Exhale to lose fat ) explaining how, when we lose fat with a calorie deficit, the excess fat mass is lost through exhaling carbon dioxide.
A study published in the British Medical Journal in 2014 supports my explanation, which I wrote based on the scientific understanding of fat loss, as opposed to all the goofy myths out there.
The study is being presented as a breakthrough way to comprehend fat loss..
Except that I wrote about this a year before this study was published, the Mayo Clinic has an article on it, and the Youtube channel Veritassium also did a video on it in 2012.. each long before the BMJ study was published. Plus this is the basic biochemistry I learned in coaching courses over 20 years ago.. not new stuff.. forgotten and ignored by most, but not new.
I'm glad the study was published and I hope there are more like it to put a dent in all the misinformation out there.. but.. breakthrough? Not so much.
In addition to providing the empirical measurements that showed definitively that indeed, all the fat lost during weight loss can be completely accounted for in carbon dioxide and water, 100% of the time, the researchers also did a survey questioning doctors, dieticians, and personal trainers about the physiology of fat loss.
Zero personal trainers knew the answer. No family doctors knew the answer. A few dieticians knew the answer (real dieticians, not the phoney ones who sell you BS fads).
Over 60% of those surveyed mistakenly believed that fat mass is lost to heat and "energy".
Some thought it turned into muscle, some thought it was lost in faeces, and some, thankfully, were able to admit they didn't know.
Slight issue with that mass into energy thing.. when mass loss does actually go to actual energy.. it's under very specific circumstances.. like inside a star when hydrogen is fused into helium and a photon is produced, ok.. lots of photons, and lots of heat. Even that mass loss to heat and light is proportionately small.. nowhere near the comparative mass converted to energy rate proposed by so many for explaining fat loss in humans. So unless everyone losing fat has more density than a black hole and is losing huge mass on a quantum level, then it's pretty safe to say this myth is busted.
Only a caloric deficit causes fat loss. Fat is made out of carbon, hydrogen, and oxygen. When we use up our fat stores to make our bodies move, 100% of the carbon, hydrogen, and oxygen atoms can be accounted for.
There is no quirk of metabolism that hides away some mystery fat.
The food we eat is made of.. yep, mostly carbon, hydrogen, and oxygen. Stored fat is made of the same stuff, and we're left over with exactly the same amount of these atoms we started with; all is accounted for. We can weigh the water and carbon, as was done in the BMJ study, and it weighs exactly the same amount as the fat lost, which weighs exactly the same amount as the extra food calories when we overate.
Calories in, calories out. Don't let any of the hucksters fool you with their pseudo science.
The main issue with successful fat loss isn't understanding the physics, it's understanding ourselves.
We become entrained in overeating through a combination of cultural influences (eat! eat! eat!), altering our appetite regulation through continued overeating and poor sleep, and using food as a soothing escape from things that cause us emotional turmoil.
We don't want to face these overeating issues because it's emotionally difficult to do so. It's hard to change, hard understand the connection between food and escaping our difficult issues. It's hard to admit that when we view overeating as a worthy celebration, that we're actually justifying harming ourselves over and over again.
In the 30 years I've been doing this, the only folks who have successfully lost weight and kept it off for more than 5 years, have been those who have found a way to come to grips with the complex emotional issues that drive the desire to overeat. Studies show that folks who lose fat permanently and never gain it back did not change their metabolism in any way.. they changed their behavior and destructive emotional association with food. They developed new healthy living habits and never stopped them.
It's difficult to change how we think, feel, and behave, but so rewarding, so liberating, and so worth it.
Why do we fall for the fat loss myths and dismiss the proven physics of fat loss? Because believing the myths is easier than facing the uncomfortable truth about why we're driven to overeat.