A person on a strict diet and exercise regimen lost 7 kg (about 15 pounds) of body fat in just two weeks. what is the most likely way that the lost fat left the body?

The fat that used will undergo a series of metabolism. The final product of the metabolism should be H2O and CO2. Carbon dioxide is a gas so it was released by lung as it was diffuse from the blood into the alveoli. Water can be removed in many ways like kidney when forming urine or sweat glands.