Have you ever wondered that? Even some doctors, dietitians, and fitness trainers have no idea what exactly happens to body fat when their patients or clients lose weight. This is what Ruben Meerman and Andrew Brown from the University of New South Wales found out.
Lungs are the main
excretors of reduced fat
The common – incorrect – assumption of many weight loss experts is that fat is only converted into “heat” or “energy”. However, this does not correspond to the law of conservation of mass from chemistry, the scientists write. The law of conservation of mass states that chemical reactions do not change the total mass of the substances involved. This means that all elements, i.e. carbon, hydrogen, oxygen etc., that your body loses, do not simply “disappear”. Rather, they are converted into a form that your body can excrete. When fat is broken down, energy is generated, in addition to the by-products water and CO2.
When we digest food and gain energy from it, breakdown products are created that we do not utilize and excrete via the intestines and kidneys. One could therefore get the idea that when we use the energy from our own fat reserves, the same waste products are created and these are also excreted through the intestines. However, this is not the case. The breakdown products of our own fat leave us through the lungs !
In an article from December 2014, which was published in the “British Medical Journal” , the two authors Meermann and Brown explain it using a chemical equation: If you burned 10 kg of fat in the laboratory, you would need 29 kg of oxygen in a combustion reaction converts the fat into 28 kg of CO2 and 11 kg of water. However, body fat is bound in tissue and cells and it cannot simply burn with oxygen like oil in a lamp.
Just “breathe away” fat?
But what exactly happens to the ten kilos of fat? The two researchers followed every single atom of the slimmed-down fat mass and realized that they were converted into 8.4 kilos of CO2 and 1.6 kilos of water. The CO2 is exhaled, the water excreted in urine, sweat, tears or stool .
Our unpleasant fat deposits literally dissolve into thin air. Another calculation by the researchers shows that this requires hard work: A person weighing 70 kilograms with a low level of activity exhales 0.74 kilograms of CO2 per day .
It is not possible to simply “breathe away” fat by taking more frequent breaths because we can only take a limited number of breaths per day , Meermann told the science portal “ABC Science”. “So there is the limit to how much [fat] you can lose in a day if you don’t exercise.”