https://www.cnn.com/2018/03/26/health/lose-weight-where-does...
"You exhale the carbon dioxide and the water mixes into your circulation until it's lost as urine or sweat. If you lose 10 pounds of fat, precisely 8.4 pounds comes out through your lungs and the remaining 1.6 pounds turns into water. In other words, nearly all the weight we lose is exhaled."