When you lose body fat it seems to just melt away. There are many different things that people are told about where the fat goes and how the body uses it so that it disappears but a new study shows that these are misconceptions on how the body works to expel fat.
A team of researchers at the University of New South Wales in Australia conducted a study on fat expulsion from the body. Authors Andrew Brown and Ruben Meerman state that there are some common misconceptions about what happens to body fat. This study may be able to clear up some of the confusion. Some people think that when fat is burned it is converted into energy in the body. Others think that it melts away when you are exercising. What the study found was that the fat is actually exhaled through the lungs and out of the body.
Fat is made up of triglyceride molecules. These molecules are made up of hydrogen, oxygen, and carbon. In order for someone to lose these fat molecules they need to break them down in a process called oxidation. During this process the fat cells are broken down into carbon dioxide. The oxidation requires the use of a lot of oxygen molecules. After oxidation you are left with carbon dioxide and water. The lungs then release the carbon dioxide that is left from the fat cell breakdown and expel it when you breathe out. Brown and Meerman found that 84% of fat that is burned is expelled through the lungs and the rest turns into water which then is expelled through sweat, urine, tears, etc.
In order for a person to burn fat they would need to inhale almost three times the volume of oxygen as compared to the pounds of fat that is eaten. This becomes much easier when someone is exercising as they are taking deeper breaths and more of them which leads to more oxygen inhalation. They also sweat more which leads to more water that is the byproduct of the burned fat being expelled. The authors of the study stated that they were surprised by how easy the process is but that this biochemistry of the body is nothing new.