When you lose weight, fat leaves your body primarily through a biochemical process where fat (stored as triglycerides) is broken down and metabolized into carbon dioxide (CO₂) and water (H₂O). Here is how it happens in detail:
- Fat cells store energy in the form of triglycerides, which are composed of carbon, hydrogen, and oxygen atoms.
- When your body needs energy and you consume fewer calories than you burn, it triggers the breakdown of these triglycerides.
- This breakdown process, called oxidation, uses oxygen to convert fat into CO₂ and H₂O.
- About 84% of the fat mass is exhaled as carbon dioxide through the lungs.
- The remaining 16% exits the body as water through urine, sweat, tears, and other bodily fluids.
- This means the lungs are the primary organ responsible for fat loss, with exhalation being the main route of fat elimination.
- Exercise increases oxygen demand and breathing rate, which helps speed up this fat-burning and exhalation process.
- Fat does not turn into muscle or simply get excreted through feces; it is chemically converted and leaves the body as CO₂ and water.
In summary, fat leaves the body mostly as carbon dioxide when you breathe out, and to a lesser extent as water through urine and sweat
